Quoted:
Hmmm....Still crops, as in my 70-200 f2.8L would be a 91-260mm, but my nice EF-S 10-22 would be unusable? Hmmm I'd rather stick to the 7D. I have to wonder why Canon would make an in-between size sensor? I guess DOF would be better on this than the 7D, but why?
The mk IV is a 1.3 crop because that's what all of the 1D series has been. The only full frame cameras are the 1Ds series and the 5D series. They originally went with 1.3x because it was the largest size sensor that could reliably be produced with the tech available at the time. Since then they have stuck with it because it provides most of the IQ, noise and DOF advantages of the full frame sensor while giving a little more reach and a high firing rate.
Quoted:
Just look at how quickly the D3 has made a real name for itself in both sports and PJ. I'm missing something, but then I'm not the intended market in reality.
That is largely because the mk III had AF issues at a time when Nikon released the excellent D3.