I also have owned this lens but have since sold it and wished I still had it. I have a funny story about the whole fiasco though.
I learned a valuable gear lesson through that experience. I bought the lens at Best Buy and the salesman talked me into a cheap UV filter. I could not take a sharp picture with that filter on, but I didn't realize it was the filter. I Put it on the shelf for about 6 months and finally sold it to a friend. He lets me borrow it every now and then but without the filter and its tack sharp! I'm always to embarrassed to tell my friend why I sold him the lens.
That was the first lens I bought that was not a kit lens, and the last cheap filter I will ever buy!!