I own a Canon 40D with kit lens (28-135 IS). In addition, purchased the EF24-70mm f/2.8 L series lens about a month ago. After using the kit lens with the IS, then using the 24-70 L series I am finding that I really miss the IS feature, even though the 24-70 is a much better lens. I just can't seem to get the sharp images, so I tend to use my kit lens more, which I know is a waste. I am shooting mostly babies and children, so using a tripod is too difficult (I tend to follow them around with the camera a lot to get those candid shots). I also prefer to shoot in mostly natural light whenever possible. I have 2 more days in which I can return the lens. I am considering exchanging for the 70-200mm 2.8 L lens with IS. It is about $600 more than the 24-70 (I paid about $1,060). But I feel like I need the IS to comfortably take photos without a tripod. However, I am concerned about the weight of the lens using it as a hand-held. Also Canon also has a 17-85 IS lens that is NOT an L-series. I am really torn about what I should do. I am wondering if perhaps my technique is not up to par for my 24-70, as I know this is a favorite and considered a "tack-sharp" lens, but I am not experiencing that. I hate to spend the extra $$$ if I don't have to. I just have "fear" of using that lens without the IS because I have worked with IS and seen the images it produces. Based on the type of photography I am doing, can anyone offer me advice? Anyone have experience with any of the above mentioned lenses? I really need some advice here. THANK YOU in advance!