9 out of 10 points and recommendedImage Quality, Constant f/4, Build, PriceOnly 12 mm wide end
I chose Tokina over Sigma, Tamron, and Canon for the constant f/4 and price, and the superior image and build quality reported in numerous reviews. My only concerns were about weight/size, focus clutch, and wide-end coverage.reviewed November 20th, 2006 (purchased for $431)
In actual use, the Tokina indeed delivers excellent sharpness wide open from 10-18mm. From 20mm up, the lens is slightly soft but sharpens up by f/5.6.
This lens feels substantial, professional, well balanced, and not at all heavy. The smooth focus & zoom rings and superb finish is very satisfying. The lens assembly is completely enclosed in and moves independently of the outer barrel, which should mean better protection against the elements and accidental bumps.
Focus clutch allows switching to manual without taking your eye off the viewfiender. This can be the difference between making and missing the shot for many cameras that won't shoot unless focus is locked.
Finally, on my film camera the lens works down to 17mm without vignetting.
To me, the only drawback is the 12mm wide end, but the longer tele end may mean fewer lens changes.