Guess this debate will never go away. If it's stopping power you want, carry a rifle. An AK with a folding stock or the AR "pistol" with no stock, just the recoil spring tube on a single point sling under your coat. Ammo capacity wouldn't be a problem either. Seriously, I've got both 45's and 9's, like them both, trust either/or with my life. MHO? If I can't stop the threat with a 9, I couldn't stop it with a 45 either. That's on me and my skills, not the rounds I'm putting down range.
Never argue with an idiot in public. People passing by won't know which one of you is the idiot.