I personally think that auto-focus is overrated.
Like most photographers who have been around for a long time, I moved from manual focussing to autofocus as soon as the first autofocus cameras started to appear in the market. I continued using autofocus until recently.
I was never quite happy with autofocus, but I didn't know why. I found that out of a quick burst of say, 20 to 30 frames, a good percentage of frames were... kind of not quite as focussed as I had wished, not as pin sharp, the focus being either a little forward or a little backward and a few were completely unusable. Basically when you focus on the eyes, you expect the sharpness to be there, with every eyelash absolutely pin sharp.
Well, it just wasn't, not always.
So I did a little experiment. I shot a similar 30 fast frames, with the model moving, with me moving up and down, close and far, as you do when you shoot models, at a rapid pace...but this time, I focussed manually. Immediately the percentage of pin sharp pictures increased to almost 100 per cent.
I tried it a few times, first auto-focus, then again manually, and as I become confident again with manual focus, to my surprise, I found that I could focus faster manually than automatically (locking the autofocus to frame the subject where you want it to be can waste a few milliseconds).
Now I focus exclusively manually, and I shoot as fast as the Broncolor packs can recycle. I feel so liberated and happy to go back to something that always works, gives you instant control as to where you want to place your focus, (or de-focus for that matter) it's more instinctive and in a way, it's a bit like reclaiming something that was lost with all this furore for auto this an auto that.
Try it, it may take a little practice to go back to manual, but provided you eyesight is good, I guarantee that you will be amazed at how much more productive you can become.