One point that has not been made yet is diameter of the bullet, expanded or not. There is no arguing that a close shot next to an artery or a major nerve grouping might not cut or damage that sensitive spot as a 9mm and miss, whereas a .45 could. That could be the difference between you being shot or stabbed or not. The ability of a round to penetrate deep is another consideration. In that case, statistics mean nothing. Actual hole size or depth of penetration could mean everything. That's why some like to use larger broadheads than smaller ones. That's why bigger IS better if your proficiency is basically similar. Only you can find that out. I know that I'm faster on multiple targets with a 9 than a 45 in similar guns. How much does that matter if only one or two shots are needed? We can't know that ahead of time. I also know the 45 makes a larger hole which may or may not matter. To the center of a lung it won't matter. To the extreme edge it will matter. It could save your life if you can handle it. There are so many variable to consider. Many new shooters are obviously better off with less recoil and muzzle blast. Many are better off with a medium sized firearm than a smaller or larger one. It pays to take the time to find all this out for yourselves and only use statistics as another guide in making your choices.