I shoot sports with a 1D IIn. I borrowed a friend's 7D for the weekend and shot a baseball game with both cameras. Here's my quick summary from a sports shooting perspecive.
AF - Close call, but the IIn was a bit better.
Nose - Outdoor, ISO 800 - no significant noise in either. I did some indoor test shots at ISO 3200 and found the noise was (shockingly) about the same. UPDATE - I did some more indoor testing. 7D beats 1D in noise by 1 stop or more. 7D noise at ISO 3200 is about the same as the 1D at 1600. Dynamic range is better on the 7D at the higher ISOs. In fact, with some NR, the 7D images at ISO 6400 are the same or better than the 1D IIn at 3200. I shot all of these in RAW mode, BTW.
Handling - Both are nice, 7D has a bit of a squared-off grip that is not so great. The 1D with the built-in grip is superior.
LCD - 7D is better. The LCD is brighter, easier to see outdoors. But, when I shoot, I pretty much ignore the LCD most of the time.
Image Quality - I found the images from the IIn were a bit better looking than the 7D. Colors were just a bit better, skin tones on cropped shots were a bit less blotchy.
6 Months ago, I considered both cameras and chose the IIn. Boy am I ever glad I did.
YMMV.




