Good morning;
An interesting array of choices. I do not have the Mamiya, so I cannot comment there.
I do have both the Kiev-88 and the Kiev-88CM, and I just missed getting a nicely reworked Pentacon Six TL. There are eight lenses from the Zodiak-8B 3.5/30mm lens to the Tair-33B 4.5/300mm lens
The Pentacon Six is a solid performer once it has been checked and adjusted by a camera technician knowledgeable about the quirky FSU cameras. Trevor Allin at the
www.pentaconsix.com web site is quite happy with his now. With the non-removable back, it does have an advantage over the Kiev Salyut, Kiev-88, and Kiev-88CM with its much greater resistance to light leaks. The frequent complaint about improper frame spacing can usually be traced to not following the correct procedure when loading the 120 film into the camera. The P-6 lens mount series is extensive, including tilt, shift, and tilt/shift lenses for architectural photography and wide panorama photographs, and there are tilt adapters and shift adapters for use with the regular lenses.
The Kiev Salyut, Kiev-88, and Kiev-88CM are a little different. The first two use the earlier screw thread mount similar to the original Hasselblad 1600F mount while the Kiev-88CM uses the Pentacon-Six or P-6 mount. Most of the lenses by the Kiev Arsenal were available in both mounts, and the Kiev-88CM can use the entire range of P-6 lenses including the CZJ, with a couple of exceptions where there are some physical incompatibility with one or two certain lenses. Some careful work may be needed to keep the backs or magazines light leak resistant. It can be a challenge. Many Kiev-88 owners just accept it as a way of life and use good quality black electrical tape around the magazine-to-body joint or a black hair tie around the joint to keep the light out. It usually works. The reliability can be really improved with the Kiev-88 cameras by having them checked by a good Kiev camera technician. We have a couple here in the United States, such as
www.mechanicalcamerarepair.com in New York, and in Europe there is Arax Foto,
www.araxfoto.com in Kiev, Ukraine. Both of these are known to be good, and Arax Foto will also do upgrades to your camera. These are only two on the list of people and organizations who still work on these cameras. I have more I can provide. By the way, if you talk to owners of the original Hasselblad 1600F and 1000F, they will also speak of their magazines being "temperamental."
Just as with the original Hasselblad view screen, there are other screens that are much brighter available for both the Pentacon-Six and the Kiev-88. In fact, if you want to, you can put a Hasselblad viewfinder screen and Hasselblad viewfinder onto your Kiev-88. They are interchangeable, and some Hasselblad owners have been known to put a Kiev Spot-TTL viewfinder onto their Hasselblad 500CM and other cameras. And, you can get some really curious looks from Hasselblad owners when they see you have a Hasselbland viewfinder on your Kiev-88.
And, for your future reference, there is a group right here on APUG for the "Bolshie Blads" or the medium format cameras from the FSU. Go to the "Groups" tab on the left side of the row of tabs along the top of the screen and look in the Groups Listing for "Bolshie Blads." I will probably be adding a list to the Files Section there providing information on many of the things just discussed with you here.