Feel free to join in. As some of you may know, I bought a Digital Rebel XT (EOS 350D) in January and have been learning to use its kit lens and the highly-acclaimed EF 50mm f/1.8 II. I feel that I've outgrown the kit lens, so I've been thinking on a short-term (2 yr?) upgrade path for long-term lenses. I'm looking at a three-lens solution: - Canon EF-S 10-22mm f/3.5-4.5 USM - Canon EF 24-70mm f/2.8L USM - Canon EF 70-200mm f/2.8L IS USM I may also add a macro lens: - Canon EF 100mm f/2.8 Macro USM I know that I could save some money if I step the 24-70 and 70-200 down to these: - Canon EF 24-105mm f/4L IS USM - Canon EF 70-200mm f/4L IS USM That said, I feel that, if I'm gonna spend the money, I may as well do it right. Perhaps I'm expecting too much from the extra 1.2 stops in the f/2.8L? Would the IS on the 24-105 make up for the loss of light? The 10-22mm lens would probably be paired fairly quickly with a 360Precision head (or something similar). I guess the real question here is this -- Would you swap the f/2.8L lenses for the f/4L IS lenses? Why or why not?