Let me google that for you
Sorry, couldn't resist.
I have it, and it's on my camera most of the time, unless I have a more specialized need or desire.
I think it tends to flare a bit more than some other lenses, but in terms of sharpness and color, I think it's fantastic, and it was a good bargain too.
Some have noted some QC issues (front/back focusing) with theirs, but with my K20D I can dial in exactly the correction my copy needs.
I understand from prior threads it has been discontinued, and that explains the deep discounts that were available for a while last year. It sold for $200 then but I don't know what it's going for now.