This lens works great with my 300D, providing sharp pictures IF the subject is within 15 meters or so. Beyond that the lens focuses further and further in front of the desired subject such that by infinity, the desired subject is noticeably blurred, while intermediate objects like the grass are much clearer.
I've been told switching to manual focusing controls the focus point but haven't tried it. Besides, it should work right out of the box or the manufacturer makes it right, which gets to my next point.
Sigma's repair center is atrocious. I can deal with a faulty lens at purchase if the manufacturer fixes the problem when I send it in. After all, we all know how quality can vary from sample to sample.
But Sigma's techs either don't know how to read or they purposely ignore people's explanations of the problems. Twice I've sent it in and twice they sent it back unfixed saying their focus tests showed the lens was "ok". At least they include the pictures they took on a CD each time so I could see that their focus tests were of close subjects, which would not show the problem, which they would have known if they'd read my very descriptive letters explaining the issue.
Anyway, if you get a good sample, good for you, but if not, be prepared to pull your hair out trying to get Sigma to fix it.