A very interesting discussion indeed. Some excellent points made, as well as some great counterpoints. Times, they do change. When I decided to move away from my 500 series Hassy system about five years ago, the choices weren't nearly as good as they are today. I went the Contax 645 route, as at that time I was shooting both film and my first digital back. With the passing of these five years, I have now used three digital backs on the Contax platform. I presently still own what I guess you would call a pretty extensive Contax kit, including two full camera bodies. My present back is a Leaf Aptus 75S, purchased originally as the Aptus 75 when it was first released. I've had problems on and off with the backs, but never an issue with either of my two bodies, nor with any of my other fairly extensive collection of lenses and accessories. The Contax kit has now long since paid for itself many times over, as did the Hassy 500 kit before it. What more can a working professional photographer ask for?
Sure, a couple of nice leaf shutter lenses would be very welcome for their faster sync speed. But I have always been able to adjust my shooting style sufficiently to compensate for that. And yes, the Contax kit DOES eat batteries, but again using the optional grips, my 2,500 mah AA rechargeable cells sure do the trick. Maybe I do need to pack four sets for a long day's shoot, but so what. They recharge in 15 mins... Most of my work the past seven years has been shooting in Mexico, under very harsh conditions. I just opened up my Apple G5 to add a new Airport card, and ended up filling a sandbag with the dirt inside it. Not once did these conditions cause a lens or camera failure. Charge my batteries, clean my sensor, load my bag, and it is off to work I went. Speaking for myself only, I am very glad indeed that I chose my Contax system. It's served me well over the years.
But that was then, and this is now. There are several options available today that were not available back then. Technology continues to progress. To a point that today, I would probably have to say that all of the present systems are good at what they were designed to do. The Mamiya ZD is very good. The H system from Hasselblad is very good, though I really do think they shot themselves in the foot when they gave up the Zeiss glass. The new Sinar is exceptional, both from it's flexibility, functionality and overall quality. It is very hard to argue with a Jenoptik back, coupled with a Rollei body & Zeiss and Schneider glass. I'm also particularly encouraged about the Jenoptik involvement in the overall system. Those guys know their stuff, and have the money available to continue to fund extensive and very expensive R&D. Don't kid yourself, for a company to survive and prosper in the world today, it takes a very deep pocket to keep on the cutting edge...
Sadly, I also would have to agree with the statement above about Leaf. They have practically painted themselves into a corner. The jury is still out though, as they have participated in the AFi / Hy6 camera platform, though as is normal for Leaf they are still ignoring the value of customer loyalty trying to derive their income from the existing base and ignoring for all practical purposes expanding the market. Had they been paying attention, David Kipper would today be shooting an AFi instead of a Sinar. And for myself, given that I also will someday soon need to make the upgrade investment, without any incentive from my current vendor it puts my future purchase very much in doubt as well.
So in the end, I guess all that matters from my perspective is that the tools I choose to use in my chosen profession need to work, get my client's job done, and done well at these prices, and provide a high degree of self satisfaction that the quality of the work I do meets my own idea of quality standards. I don't see any of my cameras as things in and of themselves, I see them simply as creative tools. Tools that allow me to capture and express my own individual view of the world. The best tools I own are the ones that do their job, and don't get in the way of achieving my creative goals.
(Sure they will not be on the same day, same light, blah, blah blah, but they may still be wonderful captures.)