If you look at the shooting records complied by the FBI, for civilian self-defense where shots are fired, in the majority of encounters 4 or less shots are fired. At that point, everyone is running away like they got somewhere else to be or they are down and bleeding out. Because, as it turns out, no one wants to get shot. So a 6 shot revolver is still actually pretty viable for self-defense. Hell, a brace of flintlock pistols might be enough......

In any case, no matter what gun you choose, you are correct - get training, practice, practice, practice. And always remember that if it ever actually comes down to it -You only have one job. Survive the encounter to get away. That's it.