Summary: I have yet to use this lens as it was purchased specifically for a trip to Africa to image the wildlife. The trip is for the first two weeks in October. I have been a user of Canon products for many years and expect this item to live up to its reputation. A post-trip report will follow.
Get the EF-III if you're on a budget. 70-300mm IS USM if you want better.
5 October 2011
Summary: It's an old lens ... the first IS lens Canon produced for DSLRs back in 1995 so the technology has gotten better since then. Don't get me wrong, it's a nice lens, but don't be surprised if the focus is a bit slow. You can't go wrong with the newer EF series 75-300mm USM lens if budget is on your mind. Even the non-USM lens EF-III is decent. Don't waste your money on this one. If you really want an IS USM lens, get the 70-300mm IS USM which is much newer and much faster.
Summary: I am happy with this purchase. I was very involved in photography as a young adult and have gotten reinvolved in digital photography after being given a D20 and upgrading to a D40. I wanted a lens that was within my budget, easy to use and good until I could transition to a higher quality, more expense lens. I use this lens to take pictures of wild-life, kids' sporting events and nature scenes. I am very happy with the lens and the pictures it takes.
Summary: I found this lens on a bid and it was my first bid at all. I saw that this lens (canon 75-300mm) was with very low price so I gave an opportunity and stard bidding. at the end I won the bid for a very reasonable price for this product.
Summary: takes great pictures. Lens is little noisy. Other than that it is a great lens for beginners. This lens is heavy and long. This is my first canon camera and the lens is a great choice. It covers great distance and for macro use this is a great lens.