I get a kick out of the "that suxors, get a XYZ" crowd, and that goes for brand and calibers both. Truly, they are the ones that hang out in the guns stores and pawn shops too long and take the "former Navy SEAL" at the gun show to heart.
Fellas... the debate between the 9mm, .357 Sig, .40SW, and ,45ACP will be eternal. Your best bet is to RESEARCH the topic and learn the truth. The following statements are fact and I just happen believe that truth will win the day.
First, accuracy is the most important factor. If you cant hit what you're aiming for then the entire arguement if moot. I've had loud mouthed deputies shoot their mouth off about my Sig 226/9mm being a wussy gun, but they have a hard time qualifying while I shoot %100 my first time out.
Second, with modern day performance ammunition (HP's, SP's, etc), the wound channels caused by any of the 4 afor mentioned calibers is far and above what is needed to incapacitate a bad guy, and they are far too similar acorss the spectrum to discount any one caliber. Keep in mind that the military uses FMJ's (non perfomance ammunition) and thus the bullet speed, weight, and design are the sole factors in determining their individual wound channel characteristics and that is an entirely different discussion. Military vs civilain uses are 2 very different things.
Thirdly, no brand of gun regardless of caliber can make up for the amount of training and expertise a person can have. By that I mean I will take a veteran from the NYPD SWAT, or other similar unit to be at my side armed with a 6 shot .38 Special SW Mod 10 revolver vs some wet behind the ears LEO or other such loudmouth who thinks his Glock 22 and his uber .40SW caliber is the best thing since sliced bread.