I happen to be lucky enough to find one of these little jewels on CL for $30.00..... and as Lt. Joe Kenda would say, "My, my, my!" Small, extremely well built, smooth as silk and oh.... SO sharp! I dare to say, other than my FA 50 & 100mm macros, probably as sharp as any other lens I have.
It seems to be very easy to hit the focus, dead-on, with ease, even with my old, tired eyes. It's just such a joy to use. But, I suppose I'm biased in my opinion, because I love some of these older, manual focus Pentax-M lenses. I wonder why it is that some of them seem easy to nail the focus and some aren't. Or.... is that just my imagination and my less than stellar eyesight?
I keep putting it off sending it to dcshooter to have it cleaned, as it has a fair amount of internal dust. It doesn't seem to effect the IQ, but maybe that's because I've never shot an image with one that's dust-free, you suppose?