I finally decided to buy the 6D to replace my 5DII and I am glad I did. But I have to begin with that somebody paid SFr. 1400 for my good old 5DII and I had to add SFr. 550 only to get a 6D, otherwise I would not have bought the 6D. This aside I can confirm that IQ is better from the 6D than from the 5DII, not much but remarkable since I don't have to apply my standard corrections anymore: The RAW-pics are cleaner and sharper out of camera than before. ISO performance is also better, but not relevant in my case. But my main reason for the 6D is size, weight, easier handling and most importantly the silent mode. I am a still photographer and therefore AF is not so important, although I also did sports and flying birds with my 5DII even with manual focus lenses. Nevertheless the surprisingly good center AF is a real advantage in low light, eg. in near darkness I press the AF-selection button to find the center AF, then manual focus my MF-Lens and get a focus confirmation where I barely can see whether I am in focus. This is a real step up. I switched off GPS and WiFi and the battery seems to last forever. And not to forget, the 6D is rugged, I do not have the impression of a second rate camera in hands. So finally for still fotographers the 6D surely is a good, conservative upgrade compared to the 5DII. Sportsshooters and videographers might have different findings.
