I switched to AF-ON exclusively back in the D2X days. I was doing a shoot with a bunch of kids on a playground and I missed the one shot I wanted above all the rest. The kids were moving fast. I focussed, kept the shutter button down half way, re-framed in a fraction of a second, and evidently let up just a bit on the shutter button. When I shot, focus jumped, and I ended up with junk instead of the best shot in the shoot. Next day I switched to AF-ON only. Yes, it took a while to get used to the change, but the effort has paid off again and again. I still can visualize what that shot should have been, and kicking yourself isn't easy, but I manage it when I remember.