Well as others pointed out, some ergonomics are regressing / not moving my way (from 40D) and for some they are more looking the xxxD/"Rebel way" (Rebel is not that negative, i had great times with my Rebel2000 ...) than the old intermediate xxD:
- only 1 custom mode (I like my 3 modes, with slow night mode landscape timer / low light inside / and BIF on C3)
- top left dial fully rotating : i liked to have BIF at C3 end of rotation like couple of you ...
- top right buttons : missing the flash exposure adjustment ... using flash fill quite a bit, and i like to be able to finetune it quickly on the spot ...
- no joystick on the back (when i play around with my previous 400D now in my goddaughter hand, i really miss the full joystick of 40D) : seem to be xD only now (7D, 5DIII...)
- banana slim remote trigger from Rebel line, cannot use my cool trigger/intervalometer from 40D (triggers are split as slim plug = Rebel, 60D, 70D // larger one = xxD up to 50D, xD)
- SD (but after recent trends i was expecting it ... CF only left on xD)
Other than that, probably great IQ (who knows with smaller photosites due to increased pix count and the division in 2) but until i test it or see it tested throughfully, right now only thing easy to see is ergonomics :-)