i am on the fence with this one. i agree with both sides really. i personally favor the 45 but im a rather hefty guy and can handle it. where as like my sis shoot the 45 and complains but when handed the 9 is fine with it. i think it wasnt the best idea for the military to leave the 45. way more knock down then the 9 but its lighter and in turn can carry more ammo which appears to be the biggest thing. and i know illcatch flack for this but it seems every one needs all the ammo they can get there hands on cuz most cant hit crap but owell just my opinion.