I too was just in the same dilemma with my 30 Sherman. It shot both 215's and 225's well, but ultimately decided on the 215's with its proven track record. I don't think you can go wrong with either one though.
I have a 30-06 w/24" barrel I load with 205gr Berger EH going 2725fps using RL17. This gun impresses me every time i take it to the range, and makes me question my need for my other big magnum cartridges.