I currently have my 15-85 attached to my 50D most of the time now. My first lens was the 50mm 1.8, then the 55-250, and now the 15-85. I got a pretty good deal on the 55-250 used and I bought it thinking I would use it. It has been over a month and I never even touched it. I mounted it to do a few test shots, but it has never been on my 50D each time I go out. Should I sell it? My only concern is that I got it for a pretty good price off POTN, what if I ever need that focal length? I mainly shoot friends' cars and portraits.