I disagree with you...6D blow away the 5D mk2 in every aspect.. don't even compare old camera with the new ones.. looks the center point AF, -3ev and high quality image in high ISO.. plus a buch of other stuff..I agree the high ISO image quality on the 6D was amazing...even slightly better than my 5D3. The -3ev is more of a spec than anything else. In practice, the center 6D focus point, even in pitch black performed about equally to the 5D3 cross type points but the other points on the 6D failed. I will admit that the 6D is slightly better than the 5D2 in AF but only slightly. I wish the 6D was better. Of course you do get wifi & GPS and while I don't like GPS, there are some uses for Wifi.
Have you shot a 6D in an actual event? Just wondering
I owned a 5D mark II for at least 3 years and the 6D is just slightly better than the 5D mark II in almost everything with the AF being the most noticeable. It's also "snappier" with the updated Digic 5+ chip. No one knew how sluggish the 5D mark II was until the next generation of full frame cameras came out, including the 6D. I don't care much for the GPS, and got bored of the WiFi feature over time. No big deal. But after shooting 4 events with a 6D already I can even go as far as saying that the video quality better. Not miles better, but I see stronger moire in my old 5D mark II footage. I can also attest that my 6D's center focus point is better than my 5D mark IIIs center points depending on the situation. I can get crowd reactions at a venue where only the stage is lit easier with the 6D's center point when my 5D3s would just hunt at center with the same lens. I'm not sure how you got your results in pitch black, but honestly... pitch black testing? How did you see your subject in pitch black? =P Anyways, I wouldn't call it just a spec, I'd rather call it getting the shot when another camera can't, especially
against the 5D mark II. I admit, moving subjects are a different story with the 5D3 but you might want to get your 6D checked by Canon support. I wouldn't underestimate the center point.