What does everyone here tend to use for autofocus modes? My default always used to be one shot AF unless I knew specifically I was shooting something with action. But since our 15-month-old son is always on the move, lately I've been leaving the camera in AI Servo, even for static shots (since I never know when he's going to take-off again). Is there any real disadvantage to using servo mode all the time? I like the focus confirmation with one shot but also like the continuous focus of servo. I've never really tried AI Focus...in practice is it actually useful? Is it the best of both or another compromise?

I know all modes have there uses and I've been trying to get better at switching on-the-fly, but I was just wondering how everyone else handles autofocus.

Stephen