I recently (this week) bought the Tokina 11-16mm lens off eBay.
The performance is about what you'd expect, good, but not sensational.
Have a look at the images on
http://www.siriuscybernetics.org.au/...t_Lovejoy.html
to see what you can expect.
Adobe Lightroom also had lens corrections for the Tokina.
Cheers
stuart