Considering the lens that I've been shooting heaps with lately is the 40mm limited pancake, I expected to be seeing 'soft' shots with the Tokina... nope.
Don't let the price fool you on this one. Full metal construction, quality feel to it, very good even wide open (no vignetting that I can see), and very sharp thereafter - from 28 to 105.
Tokina
I paid $64 at Adorama (used, rated as DEMO, and arrived like a NEW lens) - this feels and shoots like a $500 lens to me. Even gives me 'Pentax' colour, if that makes any sense.
Got it to replace the Sigma 18-125mm, wow, night and day difference in usability and results. Manual focus (and/or snap focus shooting) way faster than the Sigma auto-focus speed.
Only bummer is that you have to set the SR focal length (for shake reduction - so I just leave it turned off).
Will post some shots when I get the time.