Underlying this thread, is a lack of understanding from camera makers of the genius/engineering of Victor Hassleblad: the modular camera. The 2000 series extended his vision.
Here is my summary:
1. Square format means no format cropping in-camera. Cropping is for the darkroom/Photoshop.
2. Use any camera body with any lens or 'back'
3. Use any lens with any camera.
4. Choose a back to suit. 6x6, 6x4.5, 70mm (Phase, Leaf) etc.
(5.)High shutter speed flash sync.
(6.)Optimal quality (maybe top of the list)
The H3D is not a camera from the V.H., 500 series mould. It is a lens+body+back solution.
The whole point is that a square format did not require the camera to be rotated by hand, it was an human-centric, ergonomic solution. A 500 series camera (square format) was small; it fitted the hand; it did not require rotation. For Fashion, Weddings, and Art-reportage the 500/2000 series was hard to beat.
A squillion years ago Canon/Nikon etc realised that a rectangular format meant we; the photographers; would flip by hand between horizontal and vertical. Their Pro cameras work OK (two sets of shutter releases etc) this way. But it is not the same.
Mamiya realised that they could match Hasselblad image quality by using a bigger imaging area (sound familiar?) with a a static body,rotating back and a larger 6x7 format.
Do I sound annoyed? Of couse I am. 60 years ago Victor Hasselbald worked out that he could have the best of both worlds.(square format/superior optics) A few years later Mamiya (and then Fuji 680) matched expensive/prescision engineering with a bigger format and a rotating back. Because photographers at this level need high quality, reliabiltiy, and simple (risk-free) operation nothing has changed.
High quality, square format means crop later after using a compact, hand holdable camera. Otherwise, if the back rotates, get high quality on-site; or if the whole camera has to rotate, slow down a little/think differently. (buy 35mm)
I suspect the Rollie/Sinar/Leaf/Phase people may not have got this equation worked out: square format=compact camera; high quality rectangluar=must have rotating back.
Technology changes, human beings do not.
I know the silicon wafer/sensor dimension/yield equation, but what we are seeing ignores the job we do: making images by hand ...to sell...at a price... to people...