Thank you all for the advice. I am upgrading because I really want to be able to capture wildlife, especially birds in detail so I need something that has the ability to get good shots from a distance. I also want the speed to capture them in motion. I still want to be able to do my insect macros, so I will definitely pick up a good dedicated macro lens. I am still torn on whether to get the 2 sigmas or the one canon lens.