I am now a .264 junkie! The bc's and sd'd are some of the highest of all the calibers and there is a bullet weight for almost anything in North America. Probably the most under-rated caliber in existence.
That said, the .257 Roy has absolutely no flies on it. They'll both do the same things very well. Pick your favorite, as you'll never remember the logic only the things you wish you'd have done.
