Wow, $2,100 and Nikon doesn't even give you a full metal body? I hope Canon isn't so cheap with the magnesium alloy. You can get the 7D for $1200 and the body is a tank. Hopefully the 6D will be the same. 
7D, built like a tank, but rebel-like IQ. Even 650D is better. 
citation required . . .
No need. Sensor is same with 550D unless you dispute it.
Yes, the 7D, 60D, T2i/550D, and T3i/600D use the same sensor. The 650D adds on-sensor phase detect AF. You're saying the 650D has better IQ than the 550D/600D/7D...and if you're making that claim, you need to back it up, because from the testing that I've seen, there's no meaningful difference in IQ.