Back in the 1930's, that great authority of the Springfield rifle, captain Jim Crossman, once said "It is the right of every freeborn American to purchase a rifle chambered for a cartridge other than the .30/'06. Butto do so is no great tribute to his intelligence." The same reasoning applies to buying a 9mm rather than a .45 ACP!! That is, of course, if you are seeking something for self-defense rather than for plinking beercans with cheap ammunition...... at this, the 9mm shines! (As the troops in Iraq and Afghanistan are unfortunately learning....)
I agree if I have to shoot someone I would much rather have a .45 in my hand than a 9MM anyday. I seen a guy get shot 3 times in the gut with a .38 and get up and run off. The guy that shot him sold the .38 the next day and bought a .41 magnum and said the next guy he shoots is going to stay down. The guy he shot got dumped in a hospital parking lot the next day and died 2 weeks later. He was stealing cars when the security guy caught him and the guy shot at him and he returned fire. If I got on for self defense it would be a .45 though right now all I have is a 3 .22 target pistols though I can put several rounds between a persons eye with it before most people can get a single shot off with a larger gun.