Kathy,


I shoot professionally and once I sold my 5D and decided to go with a crop body (40D) I bought the 17-55 F2.8IS. It's a great all-purpose, leave-on-the-camera lens. While it's as fast as the 24-70L, it has IS so it can be hand-held at slower shutter speeds. It is sharp as a tack. It is a bit heavy and it's every bit as well-made as the 24-70L. When I shoot events, I need the wide end and I also need the 55 end for portraits. It is just a tremendously versatile lens. Also, it holds it's value in terms of resale. If you decide to go with an APS-H or Full Frame body in the future, you'll be able to sell this lens for virtually what you paid for it.





I've owned and shot the 24-70 F2.8L and the 24-105 F4L IS and both are very nice lenses but neither is sharper nor more versatile than the 17-55 F2.8IS, in my opinion.





Jim