I go with shot placement.
I voted .45 only because I didn't get to pick ammo. I honestly believe hot 125-gr HPs in a .357 (just an example) may actually cause more tissue trauma than 230-gr ball ammo in a .45, but it doesn't take me very long at all to draw, aim, and hit with my M1911, and hits are a GOOD thing. I like .357s but if I have to carry, it's usually .45, and I never feel like "ooooh, I should have packed a .357 instead....."
And like the guy said (I love this) "a .357 bullet may or may not expand, but the .45 bullet will not shrink." Cool. Elmer Keith once said that big bullets let out a lot of blood and let in a lot of air.
The .357 crowd isn't undergunned.... but neither am I.