An LEO buddy of mine was in a lot of gun fights.
The only caliber he would carry is a .45.
Why?
He said, he shot more than one criminal with a 9mm and they didn't go down without further hits.
Every criminal he shot with a .45 went down now, no waiting.
Hard to argue with success.
I prefer 9mm, due to great improvement made both ballistically and metallurgically, but primarily because of economics. I don't know precisely what my friend was shooting in 9mm, but he's been retired awhile and the 9mm ammo he used may have been inferior to what's on the market today.
It WAAAAAAAAY less expensive to practice shooting 9mm vs the highly costly .45 practice ammo.
I think a high quality Speer, Gold Dot, 124 grain, jacketed hollow point or a 9mm Luger HST 147 grain, Federal Premium Personal Defense will get the job down for self defense if the criminal is hit in a vital location with a 9mm. It's like real estate...location, location, location.