I echo Mark and Ken, the 5DIII is an incredible camera, especially going from a T2i! Unless you are doing huge, and I mean huge 30x40 and larger prints, I think the newer body is a little overkill. I agree with Ken as well on the idea of taking advantage of the crop sensor as well in the 7DII. However, the image quality of a Full Frame sensor is above anything on the market. The T5i is a great option as well, the build quality in the other bodies is a big step up as well.

Great photography is not about being in the right place at the right time, it is about putting yourself in the right place at the right time.