[normhead]

Over the last few years Pentax has been improving overall lens quality. Th 16-85 is kind of the pinnical of that. Its a 17-70 with more range both ends and better optics and definitely the APS_c "do it all" lens of the future. I'm not switching from my 18-135 because the 135 end of mine is very heavily used. You have to pay some attention to your shooting habits.

But just from user reviews, images etc. the 16-85 is the head of the class right now unless you want the extra reach. I can't imagine that there would be any reason but price to us a 17-70, it's not as wide, not as long, not as sharp, and look at all the 17-70 people who had buy two copies to get a good one. That's one scary lens. That being said, for a good price you could make it work.