I'm thinking of getting this lens, Canon EF 28-135mm f/3.5-5.6 IS USM. Anyone have any experience with it? If so, would you recommend it? It will be used with a Canon 20D. So far the only other lenses I have are the kit lens (EF-S 18-55mm f/3.5-5.6) and the EF 50mm f/1.8. I'm looking for something with a little bit more range and better quality than the kit lens.