5D Mark III + 85L (AF Tracking)

The new AF tracking algorithms are extremely efficient. With the right set of AF point selection and AF tracking modes, the lens never goes out of focus, hence, never hunts from infinity. The minor focus adjustments are quite fast. It's obviously never as far as 70-200 IS II, but to be honest with you, I don't see myself using the zoom anymore.

I don't know about that. I shot volleyball tonight with a 1D4 and 5D3 and swapped between the 85L and the 70-200/2.8 II for all shots.

The 85L is very good at tracking but it is still a slow lens when you want to move between targets. With either camera and the 70-200/2.8 II I can shoot the pass, set and hit in a series and expect the lens to keep up with me on all three.

I never got a single such sequence with the 85L. Pretty quick I abandoned the set. It's almost possible to get the pass and hit with the 85L, especially if both are at a similar distance.

But in the end, nope....the 85L is still not a fast moving lens. It can track action but that does not make it into an ideal action lens.