Hi,
I got a good deal on the mentioned lens and have to say that I am very pleased with the build and image quality of it. I'm using it on a D7100 body and the resolution holds up to the sensor very well.
I've only had it for a couple of days, but initial testing shows promising results. Of course, initial subjects being local cats It's lighter and smaller from the DA*300 I'm used to from Pentax, but it doesn't have a motor so that might account for some of the weight and size loss. It's handholdable with sufficient shutter speeds. The AF is slower than an AF-S version of course but gets the job done.