The 45ACP doesn't offer real advantages.

[BlackKnight]

I agree with certain things, but disagree with others. I'm a big fan of the 9 as well as the .45. Forty, not so much.
All things being equal, the bigger the round, the bigger the hole, the bigger the trauma. But, we all know things are not always equal.

[Gatorade]

A well placed 9 will have the same outcome as a well placed .40, .45, .38, .357.

I am starting to lean towards 9 just because it will give me 2-6 shots more to get that well placed hit.

[BlackKnight]

Originally Posted by Gatorade

A well placed 9 will have the same outcome as a well placed .40, .45, .38, .357.

Amen! I've investigated hundreds of cases of people getting shot. I've seen people getting killed from a .22 all the way up to .223 as well as shotguns. I've also seen people survive those calibers.
What I've learned is that shot placement is more important than caliber.

[DrHenley]

That said, technology has come a long way in the century-plus since the .45 was invented. Simply put, modern designs, metallurgy, hollow-points, and practicality have pushed other calibers to the fore as the “best” in a respective category.

Technology has advanced with 45 bullets too...