I have had some issues with poor AI Servo function on the 60D, but only with fast, small objects (flying birds). Otherwise I'm pretty happy to use center point combined with back-button focus.
At least for my own use, I think I'd miss more shots from accidentally turning the mode dial and inadvertently setting it to some completely inappropriate setting than I would from some difference in AF ability. The mode dial lock was a big reason I upgraded from the t2i. That being said, I don't do much video so that isn't a factor for me.