I think this is a great thought out thread. I carry glock mainly because that's what I grew up on learning to shoot. Played some with my dads S&W .357 revolver but really loved glock. I've tried other guns I just keep going back to glock. What can I say you stick with what you know and like. I shoot both the .45 acp and the 9mm just as well with glock. I care .45 ACP mainly for the stopping power but 9mm can be just as effective. Its all personal comfort level. I know people who like the .380 auto. Even a .22 cal can be just as lethal. Again preference and comfort level. Forget all the hype and other BS. Just my thoughts.
PS. I would want to be shot with any caliber bullet. that would be no fun no matter what size