7D, 60D, Rebel T3i in terms of IQ only

Thanks. I did compare the three camera's studio shots using this link:

http://www.dpreview.com/reviews/canoneos600d/18

... and in RAW mode at 3200 and 6400 could see no differences between the samples.

There may be differences in JPEG's attributable to different internal processors, but I only shoot RAW, and so in-camera jpeg processing isn't an issue for me.

Dan