Actually, I can only add my voice to previous speakers. The lens is the hammer, the imaging performance invariably damn good. But the lame autofocus drives me insane. Eternally long zooms and subsequently corrected. I take the AF of sheer frustration out already. Perhaps there is a hint here for me? Addendum: With the new update it's faster, now the AF is "only" still quite noisily. Sounds like sand in the gears, but with a new lens can not really be.