Originally posted by stevebrot I agree. The fact they are playing with the Big Boys (Pro/Semi-Pro medium format) pretty much means they have to have tighter control over post-sales support.
It is difficult to explain, but noise is probably a bigger issue for landscape people over resolution. The 645Z has very, very little of the former and tons of the latter. The new Sony sensor is supposed to have very low noise due to its BSI design, but how low at the 40.2 density is the big question.
As for portraiture...more detail is usually not that good a thing. More important is tons of DOF control which medium format cameras have in spades.
Ah but if one is shooting MF landscapes, I'd imagine they'd be using a very sturdy tripod. So would ISO really matter? One can drag the shutter all they want to properly expose.
For portraiture, that is likely in a studio environment thus with controlled lighting so ISO doesn't seem like it would play a big role there either? I just don't see high ISO induced noise being an issue. Actually, I don't see it being at issue at FF so definitely not at MF sensor sizes.
I think modern FF is the 'close enough to rival, yet (slightly) smaller and (definitely) lower cost option'