I got the 6D for about one year now.
The least description of 6D that makes me happy "owning" it is that:
"The 6D is better than 5Dii in about every aspect."
And 5Dii have took a lot of great pictures.
Just sharing what I thought about the AF of my 6D.
Im very amateur and shoot still people.
And I really dont check and compare if focus was spot on.
At decent light like normal house room with fluorescent lighting or sunlight outside or soft light outdoor.
Outer focus points works.
I am happy with 6D Outer point AF, can't say much.
And I am using the Un-sharpest Lens of all: EF 28mm F1.8.
( i am the only person who love 28mm, not to wide and not too long for 1 meter distance shot)
And the cheapest lens of all: EF 75-300 F4-5.6 iii
picture from EF 75-300: https://www.dropbox.com/s/ic0hcyf4gzncd18/IMG_4315.JPG