Maybe I'm naive, but I just can't imagine there's much you can do with a d800 that you can't with a 5d3. If there's a red tinge in Canon sensors, can't that be fixed easily in LR or Bridge? And I own the 16-35l and, again, I cant imagine a lens could be much better. I make my living from photography (mostly people) and there's very little the 5d3 won't do. As for MPs, 21 is 10 too many for most of what I shoot. I often shoot in RAW medium (or whatever its called) so I don't have to juggle and store massive files.