I am currently using 24-70 F2.8L and 70-200 f2.8L IS with my 50D. For my needs 24mm is wide enough for me. Unfortunately, with the 50D, my 24-70 is actually 38-112mm. I have got 2 choices, buy 16-35 f2.8 or change 50D to 5D2. I feel that it is more economical for me to sell the 50D and buy the 5D2 than to buy the 16-35 as I will end up with 2 bodies and 3 zoom lenses. Considering that I am just a hobbyist, I believe that a body and lens coverage of 24-200mm is enough for my travel photography. Not only that, it is also a cheaper move with added benefit of full frame and more pixels. Your opinions is most welcome.