When you say, "A .45 will put the bad guy down" keep in mind it isn't immediate.
I have read local accounts of many guys taking .45 ACP and appearing uninjured. But I have personal experiences too.
I have witnessed a man take two direct hits in the chest (at close range) from a .45 ACP (230 grain Black Talon) turn and run over three blocks, pausing to shoot back occasionally, before finally collapsing.
While the shots proved ultimately fatal, he was not knocked off his feet, neither was there any physical indication that the rounds struck him. The officer firing the shots (which were ruled justifiable as the suspect pulled his gun and leveled it at the officer) thought he had missed until the guy collapsed into a pile.
A three block run is no small feat in perfect health. I have no doubt he could have fought wildly had he been inclined to.
In November of 2006, George Deeb was shot 17 times with .40 S&W and .223 engaged officers, reloaded multiple times and scored hits on moving targets, and still had to be wrestled into cuffs.
I carried a 1911 for many, many years, but I never felt as though it was the Hammer of Thor either...FWIW