Can you compare to the T3i/7D? Will 6400 on the 5D3 be better than 1600 on T3i/T2i/7D? From my own experience 5d 6400 looks a lot like 7d's 1600. So I think you 'll be happy with what you ll get!
Thanks so much! And RLPhoto too.
Good luck guys.
I also agree on the 24-70 II.
The existing 24-70 is the one lens I would pick if I could only have 1 lens for life. If I had to sell every other lens to get the 24-70 II, I think I would! Gonna be awesome.
That and the 70-200 and you are covered for 90% of pro work, then fill in with your specialty: 24L, 200L, Tilt Shift, etc.