Used 60D or new 650D/T4i?

[Marsu42]

agree...using the servo and central point the AF is erratic, but the firmware it's not crippled … this kinda autofocus Always worked this way, from 40D to nowadays

Well, then let me put it another way or I'm getting flamed by some well-known Canon enthusiast: The firmware of 40d-60d has only very basic features for servo af, namely turning it on or off. One thing that would be easy to implement is to tell the camera how long I can move the af frame away from the tracked object before the camera searches for a new object for lock onto.

[scrappydog]

The firmware of 40d-60d has only very basic features for servo af, namely turning it on or off.

My attempts at getting decent AF-Servo shots with my 60D has always been a disappointment.  It is either my skill or the camera.  I assume it is my lack of skill.

[alan_k]

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.