Hello, i just got mine for 170 dollars yesterday, and i am satisfied with the image quality, altough i haven't taken that many pictures yet.
Just wanted to ask you guys one thing, i am new using sigma lenses and the zoom knob seems to be normal from 70 to 135mm and from 135 to 300 is a little bit hard to rotate and moving like in steps. (I am comparing it to my Canon 18-55 which rotates smoothly).
Did you have the same problem or is it my lens only, other than that, the autofocus is working and it works perfectly with my 300D.
Thanks guys for your reply.