Well, I for one was on the fence about this lens with some people saying it 'isnt up to the level of the fa* lenses' and others saying 'greatest thing since sliced bread (maybe better)'.
I can not speak for anyone else, but I have had to save for the better part of a year to have enough money for a 'good' lens and I didn't want to purchase the wrong one. I had been waiting for the 80-200 EX DG Sigma f2.8 (which now seems to have gone away, Sigma doesnt even list the Pentax mount as coming soon on that lens anymore) as well as other longer $800.00 to $1000.00 lenses then the 50 - 135 FA*.
However, I respect Ben's ability, skill and opinion enough that his satisfaction with it was what pushed me toward purchase.
It arrived yesterday and as soon as I got home I corralled my daughter and tried it out..
This is the result (in jpeg straight from the camera only PP was to shrink it).
I am now fully aware that any shortcomings in photos taken with this lens are a result of my lack of skill and NOT this really sharp lens.
Thanks Ben!
-John