I am trying to decide on a backup body for wedding photography. My main camera is a 5Dmkii and I have a budget of $2000 max. I am trying to decide between the 7D and 6D at the moment, and can't make up my mind. I initially thought that the 7D would be a nice option because it would provide me with a crop sensor to contrast my full frame 5D, which would give me more reach with my 70-200 during ceremonies and such. Since the 6D can currently be nabbed for under $2000, my head has been spinning. My main concern is that the 7D will not be able to deliver in low light situations and I will be disappointed with my purchase. I've heard the 6D really rocks at high ISO, but I feel as though I would essentially just be picking up another 5D...which I guess isn't really a BAD thing. Any advice folks? Is the 6D worth the extra couple bucks for the ISO alone in a wedding scenario? Is low light auto-focusing any better with the 6D in comparison to my 5D? Thanks in advance for any advice!