Originally posted by slip this lens, as well as the DA17-70 are the two lenses I avoid like the plague
Randy
You are missing a very nice lens in the 17-70. My dad bought one that was refurbished by Pentax - he purchased it used from another member. The refurb was after the SDM fixes were rolled out (supposedly). It has never given a tiny bit of trouble. Since the cost was under $200 I figured it was a throw away lens if it died and worth the risk based on how nice the lenses are optically.
The 16-50 is no big deal. It can easily be converted to screw drive and doesn't really pose much of a problem for a non-pro. A pro might find the potential for failure in the field to be too risky but I wouldn't worry too much. I own the 50-135 (actually dad has that one) and the DA* 60-250 and DA* 200 all of which have SDM and none of them have any problems. SDM issues are not illusions but they seem to be very oddly distributed with some people getting multiple failures and others never having even one failure. I am of the opinion that something other than the motor also contributes to the failures (friction, use patterns, etc.)