[normhead]

The F 70-210 is pretty fast too.

[savoche]

By far the WORST performer I've found is the 100mm f/2.8 D-FA macro. It was a laggard on my *ist-DL, and it remains so on the K-5.

I like it much better on the K-3. Still slow, but less so. And I love the output. For me, it went from just ok on the K-5 to a definite favourite on the K-3.

Fast focusing, I agree that the 18-135 is very quick, especially in good light. And I find all the small primes plenty fast enough for me. Have never thought too much about it.

It seems the 31 and the 43 can sometimes struggle a bit with obtaining correct focus at all. Not hunting or anything, just locking focus completely off. Most of the time they are fast-ish and accurate, though.