i have a sig 226 in a .40 and my dad has a sig 220 in a .45. they are pretty much identical weapons, and i have put a lot of rounds through both. i actually prefer to shoot the .45, i like the recoil a little more and its easier to control. i am a better shot with my gun, and i have grown accustomed to the recoil. the other thing i really like about the .40 is the capacity, having an extra 4 rounds is kinda nice. all in all its more of a preference thing, get what fits what your gonna do with it.