A WORD FROM AN END-USER, (deepest apologies for the length):
There seems to be two schools of thought that are emerging as a central decision each end-user has to weigh against their photographic needs.
MORE ADAPTABLE:
Backs such as Sinar (including an Hy6 compatible back), and Hasselblad CF backs that can be used across a fairly wide array of MF cameras via a system of adapters. Why would this appeal to some users? I would suspect there are two key reasons:
1) because a fair amount of photographers have more than one existing MF system, and buying individual "dedicated" backs for each is an expensive proposition. For example, I have always had a 645 (focal plane shutter such as the Contax 645 or Mamiya 645AFD-II) , 6X6 and 6X7 leaf shutter system ( like my Hasselblad 503CW and Mamiya RZ Pro-II) in my gear vault . 645 for mobility and location, 6X6 and 6X7 for studio and some of the speciality application accessories or lenses each system offers to solve a variety of problems. In my experience, no one MF system solves all application needs, especially if you shoot both professionally and personally.
2) the MF business is in flux with some systems being discontinued, while others move forward with new approaches based more on digital capture than anything to do with film.
MORE INTEGRATED:
to one degree or another, "dedicated" backs such as the Hasselblad HD cameras, Phase One backs, and most Leaf backs including their AFi with their dedicated mounts.
In my opinion these will tend to appeal to those with a more singular approach to their photography ... meaning they are primarily a product specialist, landscape shooter, architectural photographer and so on. I also suspect this encompasses the majority of commercial shooters that use a Mf camera and perhaps a view camera with the same back.
What Hasselblad has shown is there are extended benefits of this "integrated" more DSLR type philosophy. How far this will eventually go, and how beneficial it will be to the end user, has yet to be fully explored. In my opinion, Hasselblad has a clear lead in this approach with ever increasing uses of capture data at the software stage ... but it's a lead that is at best temporary.
THE FUTURE AIN'T WHAT IT USED TO BE:
What is not known (at least by me) is how sophisticated a cross platform system of adapters can be in sync with each different camera system's growing complexity of command & control ... and software utilization of camera system data ... all while increasing stability of operation and consistency of image quality.
One thing I can say with some certainty is that I, for one, cannot continue to fund digital capture from multiple platforms. Good, bad or indifferent, I have gravitated to Hasselblad by default as they were "first in, best dressed" to solve my photographic needs, and allowed me to use a vast collection of Zeiss lenses I already had collected. It wasn't without it's "growing pains" to do this, but it is pretty much a done deal.
This leaves me with a complete Mamiya system (645 & RZ) with an Aptus 75s back ... that I am waiting to see what provisions Leaf will provide me to migrate to the AFi (mostly based on cost). That an adapter for my RZ will be available is excellent news because that system's worth is in the using, not in the selling.
THE END-USER ALWAYS GETS THE LAST WORD:
One last word on behalf of an end user ... namely me since I can't speak for anyone else: This entire area of photography is quickly becoming a rarified
domain of the endlessly wealthy ... not just because of the increasing cost of new MF digital camera systems (proven by the price sheets for the Hy6) ... not just because the upgrade policies have become more aggressively priced ... not because some (not all) warranty extensions have come close to "extortion racketeering" ... but also because of the ancillary expenses associated with mega digital capture. Everything is expanding at an exponential rate in power, sophistication and cost. Not that one need keep up with the Jones', but one has to to keep relatively current based on the competitive marketplace ... it is still a publish or perish world out there ... where speed, quality and price still rule with an iron fist wielded by ever savvy buyers, art directors and even the computer literate public.