Pros and cons of Tokina 12-24/4 lens?

I had this lens until recently. It is actually a very nice lens. My reasons for parting with it had nothing to do with the lens. I have a 15-85mm also and I decided it would be better to have something else that goes wider than 12mm. In terms of build quality the 12-24mm is built like a brick. Canon and Nikon could learn a thing or two about build quality from Tokina. AF was fast enough. Not as fast or silent as a Canon USM but not bad either. AF accuracy with my 60D was a bit hit and miss at times. However, on my 7D I really never had any issues. Sharpness and contrast were good.