I used to work with a guy (in 1994) that carried a .454. I ask why once, he showed me 9- 9mm scars all over his back. Said he wanted something to get the job done the first time. He was a big guy and we didn't talk about how close they were to each other ..
Eh I traded or sold my 9mm's I'll go with my .45 acp I don't give a hoot about "modern advancements" in 9mm I know they'll both kill you dead but I know .45 acp has more stopping power with less chance of over penetration. But like said before shot placement is important, however I'd never carry a .380, .32, .22, or .25 for self defense but that's just my opinion..