The real competitor for this camera will not be other full frame cameras, but the Pentax 645Z
Not really. Anybody that has owned a crop camera then moved to a ff camera and then left the crop camera to gather dust knows the intrinsic difference that sensor size makes, well that happens again going to medium format digital, throw in the lack of AA filters on medium format and the differences become even bigger.
In the same way that crop can't ever deliver what ff can (though I am not saying crop cameras are not very good and have several key advantages over ff cameras in specific situations), ff will never be able to deliver what medium format digital can. The point at what each sensor size becomes 'good enough' for each individual is an entirely personal call.
I use a crop camera and a full-frame camera side-by-side all the time. I just usually use a lens on the crop camera that's one stop faster than the lens on the full-frame camera allowing me to use one stop lower ISO on the crop camera. The resulting images are virtually indistinguishable from each other.
I don't care what your opinion of the differences are, or are not, as I very clearly said.
The point at what each sensor size becomes 'good enough' for each individual is an entirely personal call.