Isn't there a video floating around here on the High Road where a trooper or deputy is having a man open a box in the back of his truck, and the man turns on the officer and tries to stab him? In that video I believe the officer shoots him....with his .45....and then watches while the guy walks around, has a conversation with the officer about why the officer shot him, and then fights with him later when the officer decides to take him to the pavement. If I remember correctly, the officer's gun was a .45 (don't quote me though) and that he didn't just "wing" the man.Hopefully someone else knows the video and can post it here.
Anyway my point is that you are talking about a few hundreds of an ounce difference in weight between a .45 slug and 9mm, and a couple of hundred feet per second difference in speed between the two. In my opinion, they are essentially the same in regards to their effectiveness in stopping a threat. Both require shot placement to be effective. In fact, it might be better for a shooter to carry a caliber they are UNCOMFORTABLE with. One that they doubt the effectiveness of. If they did this, they would be FAR more inclined to make sure they aimed their meager weapon to get the most benefit.
People have survived being shot with a .308 and larger rifles. Many of them during wartime. Some of these people have continued to fight for long periods of time after being wounded. Arguing about which bullet is better at the pistol level is ridiculous when we know that even rifles are occasionally ineffective in stopping a threat. None of the pistol calibers are truly effective, truth be known, and arguing about the effectiveness of one under powered pocket slug thrower versus another underpowered slug thrower...although amusing to watch and occasionally participate in...seems pointless.