woo~
Loving it at the moment. Just spent the last few nights toying around with AF microadjustment. My 24-70L was spot-on, but the Sigma 10-20 was backfocussing a bit. I've got to find a 10-metre setup so I can work on the 70-200L and the Sigma 18-200 OS, and also later the Nifty Fifty.
It feels a helluva lot more solid than the 400D - not just the weight but other things like the flipping of the mirror. Noise is good, although I'm not planning to go onto high ISOs anyway. Finally, going from 3 to 6.3 FPS is just bloody magic.