The problem is that people want to fixate on a single factor in a complex question.
What is the nature of the target? Average guy? Stoned on something unpronouncable? Enraged and bent on destruction?
Where is the hit? Through a muscle? Spine, lung, heart? Hit bone or not?
What is the target wearing? Leather jacket over a sweater and shirt or a wifebeater and a gang tattoo?
What bullet? LRN, generic HP, high tech HP? Lead, all copper, JHP?
I am kind of a history buff and have dozens of books written by WWII vets and Vietnam Vets about their experiences. I am struck by the tales of soldiers, sailors and airmen who were wounded by aircraft cannon, crewserved weapons and fragments from gravity bombs and continued to function.
There was a Japanese pilot who was wounded in the face by a .30-06, his eye was put out and he flew back to base and landed his plane with part of a .30-06 bullet in his eyeball. On a more extreme example there was a B17 crewman who carried a burning incendary bomb out of the bombbay and threw it out of the plane while it burned both of his hands off. Many Vietnam chopper pilots were wounded by 12.7mm HMH fire and continued to fly long enough to complete the mission or at least land, depending on where they were hit.
People are unpredictable, there are no simple answers and all you can do is play the odds. I carried a 4" S&W with LRN ammo for 4 years, I would carry one again, but you can bet it would be with the best hollowpoints I could find. (I carry a .45 ACP 1911 now, just for the record.)