I'm able to only echo that. 1 could possibly be "greater" than the other with regards to the requirements. Commonly, the 9mm has my vote and I have far more 9mm handguns than .40S&W. My two PPCs may also be 9mm (Sub2000 & CX4). That said, I do such as 40 S&W a great deal and just bought a Beretta APX that I really like.Certaindeaf mentioned: Inside