I just wanted to say thank you for writing such a comprehensive review. I have been overthinking which body to purchase. I hunted around for a review like yours to help me get more context. I actually sold my 5DM2 & 5D to make room for Canon's 2012 bodies for a couple of additional reasons - I sometimes feel like all these technological advances actually get in the way of composing a beautiful shot, because the process of capture can be affected by so many more variables than whether you have composed and lit the shot correctly -- i.e., did you hit the right sequence of buttons on each different camera body/strobe set up, and make sure you did not accidentally switch your 600rts to optical from radio, etc
So the idea of getting to control all my strobes in group mode from the back of my camera, and possibly having two identical bodies, is really attractive. Second, I was dismayed that my keeper rate with the 5DM2 actually got worse, when I expected/hoped for the opposite. In shallow DOF, low light situations, (using Canon's 50 mm 1.4) no tripod, real-world moving subjects, the M2 missed more often than I thought was acceptable.
So .. enter the MKIII/6D debate. I wondered if getting Canon's additional AF points in the MkIII would improve my keeper rate. At weddings, I like to drag the shutter and freeze action with a reduced power flash to keep everything natural, and keep the camera on center AF, although lately I've been experimenting with the "all/any" AF points option to see if that would make a difference. Based on your experience (and asking for input from any other 6D users out there) is the improved center AF point enough on the 6D enough to make up for the gap in other cross sensor points compared to the MKIII? I primarily shoot weddings and events.
Thank you! Tara