I have no experience with this lens, but do you need the f/2.8 from it? Have you looked into the Canon 10-22 as well?

Reading a review of the Tokina I read "On most lenses you have a switch but here you have to push-pull the focus ring in order to change from AF to MF. This is something that we find not so practical at first and it takes time to get used to." You sure it's broken, or is it just weird?