Originally posted by Unsinkable II I don't have direct comparisons, but with something like the 35-70, screw-drive AF is brutally fast (as in feel the torque).
AF is also quite fast with my F50, and even with my 18-55 WR. That's a testament to the quality of screw-drive AF in Pentax lens. But it doesn't imply that SDM is bad just because screw-drive is fast
anyway, Pentax never claimed speed improvements, they claim silent AF, and there they have it right. Silent AF is a boon in many situations.
To really evaluate the AF speed you'd have to get a K10D without the latest firmware update and another one with it, and mount a DA* lens. And then if you mounted that lens on a K-5 II you'd again see a difference
A big one I'd bet.