Thank you, Mike. It is all about keeper rate. With my old rig, I can get some sharp pictures, but percentage was much lower.
That 55-250mm STM is a great beginner bird/wildlife lens. Very cheap, super lightweight, quiet and fast AF, sharp for the price, it got me into bird photography.
It really is all about keeper rate. That's why I've got my eye open for the Canon 7DIII (if it ever come out), the 1DX mkII, or maybe even the Nikon 500D. I'd prefer to stay with Canon since I'm used to them and don't want to have to learn a new system, and purchase new lenses. I would prefer to stay with an APS-C body. That's why I'm holding my breath waiting for the 7DIII.