Ok thanks for all the info. After thinking about this I am beginning to wonder if I should buy a better lens instead of a new camera body. Got several I have been looking at, 70-200mm f/4L, 300mm f/4L IS, and the 400mm f/5.6L. I have a 55-250mm f4-5.6 and it has worked well for me, from photographing an Eastern Diamondback to barely getting a Bald Eagle on a sandbar. I'm just not sure if the 70-200 would be a good upgrade to the 55-250 or not, or if I should get the 300 or 400 first. I've never owned or shot with an L lens but I've always heard they are the top of the line Canon lenses.
Canon Rebel XT, t3i. EF-S 18-55mm f/3.5-5.6 IS II, EF 50mm f/1.8 II, EF-S 55-250mm f/4-5.6 IS II, EF 100mm f/2.8.