I began to consider CCW after 3 guys tried to carjack me and my wife. I got away unharmed, but considered myself lucky. So, in that situation, I think having a 15 round 40 or 357 sig far outweighs any advantage a 45 would offer since they typically only chamber half as many rounds.

Also, the 357 Sig and 357 Magnum are supersonic (that is why they are louder than other rounds). So, right behind the projectile comes a shockwave that provides an added measure of knockdown force. All other pistol rounds are subsonic.