NICE!!! I actually got to try this lens out in person.
I needed a cheap wide angle lens and it was between this and the Sigma 20 f1.8. I have to say though, this lens is really built like a tank. Focusing is SMOOTH!!! I think as smooth or smoother than my old 17-40 L. In the end though, I ended up getting the Sigma 20 f1.8. WHY?? here's why:
I love the 17-40 f4L!!! It's just the perfect walk around lens (27-65 on a 1.6 body). I know that when I broke my old one that I will be replacing it no matter what. The versatility, the sharpness and the color - this lens has everything. If the Tokina lens was 2.8, I might have considered it...but its max apt is only 3.5 - almost similar to the Canon zoom
So in the end, only because of the Sigma's max apt of 1.8 (something the Canon zoom could not replicate) - I ended up getting the Sigma
Am I glad I got it??? yes...........it is not sharp at 1.8 but its there if you need it. At 2.8 though, it is already sharp.......and for a wide angle, I can handhold it even on 1/15 TV.
Okay, enough rambling!!! The Tokina is no slouch. I went home to look at the pics I got...........and they are very very good!!! impressive indeed.
Ro1