Originally posted by cheekygeek I trust end user's opinions most. If you read the Owner's Reviews at amazon.com on this lens, you may be less enthusiastic about the 17-70.
I purchased both the 16-45 and 17-70 Pentax lenses at the same time, when the 17-70 was first released, and while both are very nice, I use the 17-70 more often and am well pleased with it. SDM is awesome and super quiet. The images from mine are quite useable and very good at all focal lengths; they look good on my computer display, prints, and internet use. As far as Amazon reviews go, really, there are only 4 there and I don't usually let a few less than positive remarks about a product deprive me of obtaining and enjoying a product...........