I recently was lucky enough to grab two good deals for great medium-format film cameras and accessories. Earlier in 2018, I bought the Mamiya RZ67 Pro with two lenses - the Mamiya 110/2.8 Sekor Z and 65/4.0 K/L lenses. I purchased a Hasselblad 500 C/M (V Series) later the same year with a Zeiss 2.8/80 Planar T* CF lens, and I added a Zeiss 3.5/60 Distagon T* CF lens. 

First a quick summary of my findings where both camera systems have similarities and differences:

Size comparison between Mamiya RZ67 Pro and Hasselblad C/M with vertical viewfinders.

Size comparison between Mamiya RZ67 Pro and Hasselblad 500 C/M with vertical viewfinders. The Mamiya RZ67 Pro has the optional automatic film winder II attached

Which Camera for Which Purpose?

I used both camera systems outdoors for shooting, and carrying the Mamiya RZ67 Pro around for a full day will be quite an exercise. This camera is not made for being moved around and rather serves its purpose as a studio or tripod based camera. The rigid and heavy Mamiya camera body might lead to less vibration issues fixed on a tripod, too. In a studio, the Mamiya can be advantageous over Hasselblad due to its shorter minimum focus distance better suited for portraits and head shots. Since Mamiya lenses have no focus ring capability, and the focusing is all done with a bellow within the camera housing, a much closer focus distance can be achieved. The Hasselblad 500 C/M is a much better choice when you want to be flexible and shooting without tripod. Regarding framing, the Hasselblad will allow you to compose with a square format (6x6 cm as standard) wheras the Mamiya RZ67 Pro generally shoots with 6x7 cm (the standard film back for this camera). 

How Do You Mount or Carry Each Camera?

Both cameras can be mounted directly on the camera's base plate onto a tripod head plate. I prefer to use the standard Manfrotto tripod head plate with 1/4" screw mount. The Hasselblad 500 C/M requires - similar to my Leica M3 - a tripod mount reducer bushing from 3/8" to 1/4". Gladly I got a whole set of the bushings when I needed one for my Leica M3 which now helped me to fit a second one for the 500 C/M. The RZ67 Pro body fits directly the 1/4" screw. One difference I observed is that the much heavier RZ67 Pro is ironically better balanced with the neck strap - a lens can be changed much more easily in this position. The Hasselblad flips vertically over after a lens is detached with the lens mount pointing downwards. It doesn't make the lens change unsafe, but it is something to get used to with the 500 C/M. Talking about camera straps - I cursed several times the designer of this Hasselblad camera strap. Mounting and removing the strap with the metal locking plate mechanism is no fun and forced me several times to review the few sentences written about doing this correctly in the manual. If you are not careful, the strap slides and might scratch something on the camera. I highly recommend to attach the Hasselblad camera strap only once and leave it there (make sure it is winded correctly!). The position of the strap unfortunately is not ideal either on the 500 C/M due to its full 360 degree rotation capability - it easily gets in its way with the shutter cocking knob on one side and with sliding in and out the dark slide of the film back on the other side. The Mamiya strap is fixed in a vertical position on the camera which avoids this inconvenience. 

Talking About Film Backs and Film Formats...

Loading 120 or 220 film takes a few more precautions with the Hasselblad system: After the roll of new film is inserted, make sure to open the film plane fixing mechanism via clamp first and slide the film underneath of it before rolling the beginning of the film into the inserting spool. After the film is inserted into this spool close the film clamp again. The Mamiya film loading system is more straight forward here and doesn't use this additional film clamp. I never had the impression that a film inserted in the Mamiya film back was less evenly aligned than in the Hasselblad system. Trying to shoot directly in square 6x6 format with the RZ67 Pro is a challenge - used 6x6 Mamiya film backs are extraordinarily expensive online. Better way is to crop in post processing from the 6x7 format after scanning or cut one centimeter off from the frame in the enlarger for darkroom printing. The Mamiya viewfinder has little ear marks to allow composing in 6x6 format, too. The Hasselblad system has a lot more choices when it comes to film backs - there are multiple release versions which can all still be used on the 500 C/M. A very good overview of Hasselblad film backs is shown here:

Link to Hasselblad Backs

If you still have some 220 film sitting around, the Hasselblad system is the way now to shoot with it. I found an A24 (cartridges for 220 film have the A24 classification for 24 frames - twice as many as with 120 film) cartridge in good condition online for $40. Keep in mind that 220 film does not use the additional paper backing layer of 120 film which makes the film plane of 220 film thinner. Therefore the film cassettes are rarely interchangeable between 220 and 120 films - a few Hasselblad film backs allow to do this, but certainly none from Mamiya. General rule of thumb for Hasselblad film backs is the newer the better. Often the dark slide is scratched or has bents with the risk of failing winding mechanism in older cartridges offered for sale. Check online on websites the serial# of cartridges to determine their manufacturing date. A16 Hasselblad 120 film backs for 4x4 cm format go for approx. $70 in good condition whereas newer standard A12 ones for 120 film cost more than twice as much used. Also make sure that the cassette serial number (the newer ones only show the last few digits) matches the serial number of the film back - the backs can have quite a bit of variability in the construction - best image quality projected on the film is achieved by matching cassette and film back. 

Film backs for the Hasselblad V-series, from left to right: A12 with Lindahl dark slide holder, standard A12 back, A16 back for 4x4 frame format, and A24 designated for 220 film with 24 frames

Another a bit unfortunate mechanical construction is the design of the dark slide in Hasselblad film backs - the end with the lever is a bit protruded to one side. It is not easy to see which side is which especially during shooting - it only becomes a potential issue when removing the film cassette from the inside. If the protruded dark slide lever is pointing towards the film back, it will be automatically moved outside when the film cassette is removed. This is not a big deal, but not as convenient as with the Mamiya film backs where this is never an issue.
Hasselblad was a bit cheap when it comes to storing the dark slide during shooting. Some film backs have an added Lindahl-fabricated dark slide holder on the back which can be quite useful to have. All Mamiya film backs have as standard a plastic dark slide holder on the back.

Careful how the dark slide is inserted into a Hasselblad film back - if the bit protruding lever element is pointing towards the side of the film cartridge lid, it will be pushed out with the lid when opened (left photo). If the lever element points to the other side, it will stay in place when the lid is opened (right photo)

Taking photos in square format is something to get used to. Coming from 35 mm film, I am more used to the rectangular format. I enjoy 6x7 with the Mamiya RZ67 Pro camera, but I admit that I now like 6x6 with the Hasselblad even better. The focus on a specific object in a 6x6 frame is more emphasized than in a similar rectangular shot. Big advantage for 6x6 is the avoidance of landscape or portrait framing - you never have to flip the camera or a camera back. Another positive of shooting 6x6 film is that 12 frames fit on one roll of 120 film instead of 10 frames in 6x7. I also tried shooting 4x4 with the A16 Hasselblad film back (giving 16 frames on one 120 film), but the compromise in resolution is visible compared to 6x6. Composition is more cumbersome in 4x4 since a crop factor of 1.5x is applied. IMO it is still a good solution if you are short on a specific film, or avoid changing film too quickly. 

Nice feature of the RZ67 Pro is its ability to do multi-exposure shooting by flipping a switch on the camera side. This decouples the film transport mechanism and allows infinite exposures on the same frame. The Hasselblad system also allows doing it, but it is a bit more cumbersome: The film back has to be removed before the shutter is cocked, then the film back is attached and ready for the next shot on the same frame after the dark slide is removed. 

It's All About the Lenses!

Nothing beats Zeiss lenses made at the time when the 500 C/M was manufactured in built quality and the lenses I have are superb in sharpness. Since the manual focus system is located within the Zeiss-Hasselblad lens, it potentially can be used adapted on any modern digital mirrorless camera (MLC). Mamiya lenses are only one third of the price compared to the Zeiss-Hasselblad medium-format lenses, but they don't have any focus capability within the lens. Beginners might be confused by looking at a Mamiya medium-format lens which has a look-alike focus ring which only uses a scale to estimate hyperfocal distance depending on aperture setting. It does not have any mechanical function! 
Usage of Mamiya medium format lenses is limited to the Mamiya cameras (if no adapter with additional focus feature on a is used adapted to a MLC). Mamiya lenses therefore can't be used on a Hasselblad system. This might make reselling these kind of Mamiya lenses a bit more difficult. 
A disadvantage of the Hasselblad-Zeiss lenses is their lack of a standard filter ring thread. Instead the Zeiss lenses use a lock-in system (named with a B** (** = 60 for the Zeiss lenses I use) to attach the lens hood outside the lens barrel, and the fitting lens cap mounted directly onto the bayonet (here it is an advantage to have the bayonet - lens caps sit much better than with any other lens system I know). To use a regular 77 mm diameter filter, you need to purchase a cheap step-up ring (B60-77 mm). I can't use the designated Zeiss lens hood anymore when the step-up ring is attached. Mamiya lenses are much more comfortable here - they use a standard 77 mm filter thread. No issue to use lens hoods with Mamiya lenses since the fitting filters are directly mounted to the lens. 

Mamiya allows to use lenses made for the RB67 camera also on the RZ67 cameras. Unfortunately, the lens design was changed quite a bit between these camera versions: when attaching RB-camera based lenses (named K/L lenses) on a newer RZ67 Pro, keep in mind that the exposure setting knob on the camera is overruled by the exposure ring on the K/L lens. You can easily make the mistake and expose like usual with the camera knob and realize later after developing the film that most frames are either under- or overexposed because you shot everything at the same exposure selected on the K/L lens ring. This is because the older K/L lenses lack electronic communication with the camera. Otherwise K/L lenses are cheaper than the more modern Mamiya Z Sekor lenses, but there is another culprit to be aware of when it comes to long exposure shooting. Two remote cables are needed to accomplish this with K/L lenses: one has to be inserted into the lens body to open the lens leaf shutter after the shutter release button is pressed to lift the mirror up (M.UP insert), the other cable in the "B" insert closes the lens' leaf shutter after a given time. Tricky part is when the cable controlling the lens leaf shutter is removed - you have to remind yourself to triple-check (!) that the tiny screw-in M.UP thread on the lens body is fully immersed with the red ring NOT being visible around it. If this element remains protruded (meaning the red ring is visible!), the whole leaf shutter mechanism will be messed up in future exposures - the lens shutter will remain closed and you get unexposed frames! In this case re-insert the cable release and remove it again afterwards to have the screw retracted inside the lens body. Both culprits happened to me when I first used my K/L lens with the RZ67 Pro body - this is the reason why some recommend not to use K/L lenses on newer electronically controlled Mamiya bodies. But keeping the potential obstacles with K/L lenses in mind, they are often an excellent deal out there with very good image quality quite similar to the newer Z lenses. I have not yet tested the Hasselblad system and lenses for long exposure capability! I will update this section after I have tested it.

Tricky culprit with Mamiya K/L lenses when doing long exposure photography: make absolutely sure that the M.UP screw is pushed back into the lens housing after removing the shutter release. For normal shooting, the red ring should not be visible as shown in the left image.

The Zeiss-Hasselblad lenses use a nice feature on the exposure scale on each lens - the EV number is printed in orange and can be directly copied from the EV number shown in an external light meter. This works well in theory, but is not so practical in reality - the orange EV mark is in 3 o'clock position from the 12 o'clock distance meter mark on top of the lens. I found it very cumbersome to look on the side of the lens to find the EV mark especially when the camera is not mounted on a tripod and hanging from my neck. It is easier to translate the shown light meter based EV number into the corresponding aperture/exposure time equivalent and directly set it this way on top of the lens.
The Zeiss lenses allow to merge otherwise independently rotating aperture and exposure rings - a feature I very rarely use, but it can be helpful when for example the same scene needs to be photographed in a range of different aperture settings. Automatically the exposure time is aligned with each chosen aperture which saves time. Mamiya lenses have neither of these features (which IMO is not a big loss at all). 
One thing I found a bit cumbersome on the Zeiss T* CF lenses is the depth of field lever. By moving it into position, the lens aperture will remain at the given aperture setting and allowing a more realistic image view through the viewfinder of the applied depth of field. If you forget to move it back into the open aperture position, you might wonder about a too dark image at closed aperture in the next frames of shooting. Unfortunately this lever can easily be stuck on my Zeiss 2.8/80 Planar lens - therefore I rarely ever use this feature and leave the lever alone. 

The orange EV scale mark is on the side of the Hasselblad-Zeiss lens bodies - unfortunately not a good position to select this number when the camera isn't used on a tripod (left photo). Aperture and exposure times can be chosen separately or rotated together (right photo).

Achieving Focus

Hasselblad follows the traditional way of focusing with the camera: through the lens by turning the focus ring. The Zeiss-Hasselblad lens focus ring is located at the lower end of the lens barrel - opposite how it is done with DSLR lenses from big brands like Canon or Nikon where the focus ring sits on top of the lens barrel. The focus ring of the Zeiss lenses which I am using is fairly slim for the size of the lens. The manual focus on the Zeiss CF lenses is very precise, but it is not a fast focus system either. Especially when I want to focus from an infinity stop to a close-up distance, it requires a few turns on the focus ring to get there. Mamiya has the focus system built into the camera housing itself: A small bellow moves the attached lens back or forward to achieve focus. I found this system much faster to change the focus point. Problem here is that the RZ67 Pro has no fine adjustment wheel at the focus button (the RZ67 Pro II does), so I need to be very careful how much I turn the wheel to nail the focus within the viewfinder. A small extension or contraction of the bellow makes a big difference in lens focus! I am so far fine with either system to focus accurately, but I simply prefer lenses with focus ring. 

About Viewfinders

Both camera systems come as standard with a vertical viewfinder. It is something to get used to especially since left and right of the frame are reversed by looking onto the matt glass due to the mirror underneath. The matt glass of the Hasselblad 500 C/M can be changed - there is a variety of options available, for example with or without grid lines.
For accurate focusing at more shallow depth of field the vertical viewfinder is not the most convenient even if the loupe element is used. When the Mamiya film back is rotated, the vertical viewfinder view changes accordingly depending on landscape or portrait position. To achieve accurate focus, the loupe has to be used - feasible and decent solution, but it requires time to flip out the loupe, focus, and then push it back in. A better option to allow more precise and faster focusing is with a 45 degree prism viewfinder which provides a direct view through the lens without mirror effects.
The Hasselblad system allows to adapt all kind of newer or older prism viewfinders; Mamiya also has some for their cameras. I decided to buy a mint used PM-45 viewfinder for the 500 C/M which has the big advantage that the ocular can be rotated to fit the eyesight diopters. Otherwise additional expensive glass inlays have to be used! The prism viewfinder allows to use the camera like a SLR and shooting from eye-level (while you shoot from your belly level with the vertical viewfinder). Biggest con for a prism viewfinder is its price for the Hasselblad system - the PM-45 goes for about $400 (if you are lucky!). But IMO it is a worthwhile investment which pays off in the long term - I would say it is nearly a must-have for portrait shooting. One minor disadvantage of the PM-45 I have observed recently in cold weather - the ocular lens tends to fog easily, so always have a fiber ready to wipe away the condensed water droplets! You can get more sophisticated (and even more expensive) prism viewfinders  with electronic metering, too. I decided against additional electronics since it is another feature which might break especially when the viewfinder is an used one. Instead I prefer to use external metering with a handheld meter. 

PM-45 prism viewfinder attached to the 500 C/M camera. The matt glass remains in place when the vertical viewfinder is interchanged with the prism viewfinder

Link to Hasselblad Prism Viewfinders

So far I have no personal experience with Mamiya prism viewfinders. 

Mirror Up!

Since both cameras have a quite big mirror inside which flips before an exposure is taken, vibration can be an issue especially when shooting at slower shutter times. The Hasselblad 500 C/M has a lever underneath the film winder button which flips the mirror when pressed upwards before the leaf shutter is opened. This avoids getting a blurry image due to vibrations by the flipping mirror. Disadvantage of this method is that you can't see the frame through the viewfinder after the mirror is flipped - this method should be only used when the camera is mounted on a tripod. I tried it a few times handheld, but it is very challenging to maintain the composition in the image frame before and after flipping the mirror and then taking the exposure. 
The Mamiya RZ67 Pro can also have the mirror flipped up before an exposure is taken. But the camera has not a designated button or lever to flip the mirror up - instead you have to first attach a cable release into the long exposure lens port, then press the shutter release button of the camera which will flip the mirror up and open the camera back shutter. By pressing the cable release and holding it in open position for a given time, the exposure is taken without the mirror causing vibrations. 

Medium Format Film Development

One remark in regard to developing 6x6 or 6x7 films. High micro contrast developers (e. g. Rodinal) are not necessary for this size of B&W negative since the resolution and detail in this size is already so superb that increased edge sharpness is not needed. I prefer a low contrast developer like Xtol in 1:1 dilution which also suppresses strong grain formation. A low speed film like PanF+ 125 gets a digital medium-format look with beautiful grey tones using this developer. 
I am using Paterson development tanks with adjustable film reels good for 35 mm, 4.5x6, and 6x6 or 6x7 cm film sizes. I use nitrile gloves when removing the 120 film from its paper backing and cutting the adhesive end. Then I insert it into the plastic reel - but instead of using the back and forward movement with the reel bearings, I simply push with my fingers the film further inside the reel. 120 (or 220) films have no notches which makes this easy. I found this the best way to avoid bending the film or getting the film off track. 

Can I Shoot with a Digital Back?

Something I didn't test yet but watched videos about is adaptation of both camera systems with pricey digital backs. In Mamiya's case, only the RZ series can do this; it is said that the RZ67 Pro II is even better suited here due to improved electronic couplings with the digital back. A specific additional adapter set is needed to mount a digital back on a Mamiya RZ67-based camera. All Hasselblad cameras can be equipped in theory with digital backs since the digital device only needs to act as recorder of the captured image but has no control over the otherwise fully mechanical camera and lens parts (which is not so simple with the Mamiya). No additional adapter is needed for the Hassy - the film back is simply replaced by the digital back. But keep in mind that we are not there yet to shoot 6x6 or 6x7 digitally - the largest digital sensor close to 4.5x6 cm size was just announced by Phase 1. Any kind of digital back will have a smaller image frame than film based medium format - it comes with a crop factor and change in the field of view. Instead I recommend to shoot film and simply digitize the developed frame with a good flatbed scanner (for example the Epson V850 or predecessor series). 

Where Does This Leave Us?

Which is the more fun system to shoot with? I would answer it is the Hasselblad system. The more bulky Mamiya camera system is a hybrid of traditional medium-format technology with added electronic features which can be sometimes confusing how they play with each other (or not). I personally really like that the Hasselblad 500 C/M is a fully mechanical one - maybe a more fair comparison would be versus the Mamiya RB67 which is also fully manual. If cost is an issue, the Mamiya cameras and lenses are the way to go - the cost only about 30-50% of similar Hasselblad prices with used gear. The Mamiya cameras also give you best flexibility in the medium format size - from rectangular to square (see above regarding PP crop). Hasselblad medium format cameras are focused on square frame formats. At this point I wouldn't separate myself from any system described here - they both complement each other in functionality. Both are capable to capture fantastic photos!