Don't have it personally, but you can read some reviews here:
http://www.pentaxforums.com/lensrevi...uct=294&cat=43
It doesn't seem to get the responses I'd expect from a DA* lens, not sure why that is though.
Is it the wide angle bit that attracts you to that lens? The popular lower cost replacement lenses aren't going to be exactly the same quality, but they tend to offer more reach. Sigma and Tamron both make a solid performing 24-70ish f/2.8 which wouldn't give you as much in the wide side, but offers some reach your prime won't have.
http://www.pentaxforums.com/userrevi...uct=317&cat=74
http://www.pentaxforums.com/userrevi...uct=343&cat=76
Both will be significantly cheaper, but not have the build quality or weather proofing of a DA*