Only thing so far is I found out mid shoot that the zoom buttons for the LCD screen have vanished and so I had no way of zooming in to check how the lighting / shadow fell properly on the couple's faces.
I know there IS a way of zooming in, but the way I've always done it on the 7D aint the say way... I need to read the instructions for this aspect I think.
That's my fault though for not reading up on that 1st and from the shoot I had I can say everything was 100% positive!
A few key points I noticed were:
1) The DOF is much more noticable. I'd read it was and that shooting f/1.4 on a crop was more liek f/2.8 on a FF (or something like that)... either way with the added sharpness of the FF and the greater impact of DOF you end up with some beautiful bokeh mixed with sharp subjects.
2) I accidently blew a bit of the sky in one shot... opened in adobe bridge and selected the little arrow that shows blown areas as red. Slid the recovery slider a bit to the right and it litterally gobbled up the red. All blown areas were fixed and no impact on any other part of the pic... it blew my mind! The 7D would have maybe fixed of a little bit of the blown area but also made the skin tones go a bit 'off' in the process. The MK III just laughed in the face of the blown sky!
3) A like a punchy high contrast image.. on the 7D I always boosted the contrast by a fair bit. On this body I either didn't need to at all, or only a teeny tiny bit.
4) It's kind of too sharp at times. I foud myself softening things like the creases on the guys trousers as they were so bloody noticable!
5) Colour is rendered / captured beautifully
There's probably other things I could rave about too but I'll let you work out the rest for yourself
All I can say is no negatives at all (other than my own lack of knowledge RE zooming in the LCD screen) and LOADS of positives!
Are you excited yet?