The 7D gives a much better result for one vital parameter - pixels per bird.
Surprised at your post Hollis.
I spent some time with a friend testing the 7D against the 1D3 we, like most people, found the 1D3 a better camera IQ wise. Some time later I got a 1D4 and then his 1D3 couldn't equal it for IQ - so my friend got one. After a few years of being happy I traded and got the 1DX, again the 1D4/1D3/7D are not in the running.
If pixel density is so important why am I getting better pictures with my sensor? After all it is only the equivalent of about 7MP in Canon APSC terms. I agree there is a difference in reach but it small even with Canon's best lenses. As to the ISO advantages - well that is another story!
Note I am not comparing frame rates AF etc - that would not be fair.