Whatever you get, make sure there is good glass for it. My wife has a Rebel T3i and it does fine for what she uses it for. With better glass these would be better. the 300 doesn' have image stabalization so it could be crisper.
This was a point-n-shoot camera compared to hers with just a 300mm lens.
Or a teensy little crab with the standard lens. She also has macro lenses and you can see the pollen grains if you want.
A moose at a couple hundred yards.