9 out of 10 points and recommendedVery good IQ for a SWA, esp. at f5.6 and higher; low distortion; small and light; great build qualityA bit soft at f4
This is a little gem of a lens, very pocketable with very good IQ and low distortion compared to other lenses in this FL range. While a bit soft wide open, it sharpens up nicely at f5.6 and above.reviewed November 7th, 2009 (purchased for $580)
I question your recommendation of the Tokina 12-24 f4 as an alternative, as it is not available in the Pentax K mount. However, I believe that the Tokina shares its optical design with the Pentax 12-24 f4, so the Pentax would deliver similar performance.