I agree. I have a 7D which I limit at ISO 800 in auto ISO...I limit my 6D at 6400 and I think the noise level is better at that level than at 800 on the 7D. A very pleasant surprise.6D is two stops better or so. So if 800 is your cut-off now, 3200 would probably be your cut-off on the 6D. Anyone else agree?
That's my experience coming from a 50D, where I was never happy with >800 ISO, and that's at the pixel level so comparing 15 MPix to 20 MPix (even more in favor of the 6D IQ). I set the auto-iso cut-off to 3200 and find those images very usable, and typically don't even apply NR to 800 ISO shots unless I underexpose and have to adjust shadow levels. For JPEG even 6400 is quite good, but with raw you do have to work a bit to do as well as the onboard processor. Pretty amazing, actually.