The wider lenses from Phase/Mamiya drove many including my self to a tech camera.
28mm has never been a great lens wide open, and only really starts to get good in the corners by F11 (on some versions ) and F14 on the two I owned. Nothing wrong with F11, but my lens still did had coma aberration even at F11 and this in daylight this causes smearing of the edges, very evident in foliage and at night butterfly wings on stars, making the edges not useable. Thus my 28's (I owned two of them), were better 35mm lenses. If you use filters, the 28 as any wide with a fixed tulip and curved outer element poses a lot of problems unless a system like the Lee can be adopted to it.
The 35mm, (owned 3 of them) still have the "best" one. Not bad but still a bit soft not smeared, in the corners and just can't get to the level of details that a Schneider 35XL can.
Neither of these lenses will allow movements, you can set them up for a nodal pan, (of which I did many), the need to be level with camera always posed an issue.
As for the prices, the only thing that will drive Phase One into a realistic price point for the CMOS backs, is competition and it's pretty obvious that the 645z and 50c have not been enough yet to do anything. That may change over time. To purchase a Credo 40/80mm for 134K, I just don't see any advantage to that for landscape work, possible if you are a studio shooter as you will have an LS lens.
Phase seems to have a very good market in the far east, China, Japan, etc. and that market is huge, and more than likely will continue to drive the price points for years to come.
I also don't the Canon 50MP sensor changing the game. But it's yet to ship and not too much has is known about it.
What has hindered Phase the most seems to be their current camera body, which is overpriced and not very feature rich when compared to others. This will all change later this year when the "new" body is announced. Most shooters still don't use tech solutions, instead prefer a body with no LCC issues. So I figure for the rest of this year, once the body ships Phase will do just fine. Next year more than likely they will continue with full frame CMOS at the same price structure, so it will not be an easy move.
Phase has also could care less that a 160, which cost in the 39K range, just sold for 11K on ebay. I care as that it a huge hit for someone. Where as the price of the 250 at 22K is tempting
Paul