And when I ownd a couple of 'blads I lived in Scotland and Spain and worked in many corners of the planet, so the pictures from those things belonged where?
Economics, manufacturing ability and capability rule everything. Ever looked at your humble white washing machine, only to notice that, over the years, the whites take on different hues? Not even the bits of the body all seem to come from one supplier/manufacturer and, where they do, they are obviusly produced to a variety of different painting standards.
Basically, I think that the problem with the entire MF concept in digital is this: those cameras really don't spell out medium format as in the relatively large jump in film size that the term was understood to denote back in the day. Were sensors built proportionately larger, maintaining the film format differences and the expected advantages of real estate, then I think that those able to finance such equipment would feel far happier at the debt they take on. The underlying feeling I have is that digital MF isn't: it's an approximation, a half-hearted attempt at going there at huge costs to the traveller.