I rented both 7D and 5DmkII before byuing one of them, so I have comparison. 7D autofocus is much more better than 5D2, so I bought 7D. After half of year I'm very satisfied, I'm using 7D in low light conditions very often (iso 3200, 1/60s f/2.2)
Please note AF is not just about camera, but also about lens, I don't know how good is 50/1.4 but I can imagine many newer lens are better, e.g. AF of 17-55/2.8 is excellent and significantly faster than my 28/1.8 and 85/1.8.
I'm using single AF, point focus and all of available AF point, with my 28 and 85 all shots are perfectly focused, ny photos are blurred only if I select to long time, sometimes I have problems with DOF, but it's my issue.