of course the 6d will have better IQ than both the 5dii and 5d iii. its a new camera. I know that. Canon just wanted to make a cheap full frame. I am sorry if i offended you but it was just my two cents. I like the amazing low light performance of the 6d, it is great for a canon camera, but in my hands it just feels like a toy, maybe because it is so light compared to the monsters that are the EOS 5 series cameras. Even the 7d feels much tougher than the 6d. But for IQ the 6d obviously wins.
I have held the 6D next to the 5DIII for long periods of time, and noticed zero difference in "feel" except for the weight, which was much nicer on the 6D. I own a 5DIII.
This. The 6D is made of the same materials as the 5DIII and 7D, the only difference being the top cover which is made from high impact polymer (never going to break). And the difference in size and weight is welcomed by anyone who uses their camera everyday (as I do)
And don't worry, I'm not offended, Just don't like the smell of BS