I'm debating about some handgun choices. My son has talked me into getting a handgun. The ones I'm looking at are the Glock 19, 21 and the Springfield Armory XDM 9mm or 45. Talking with some of my local gun shops say that the difference between 9mm and 45 would be personal preference. That the 9mm now has some decent ammo for defense. I've been researching on the internet and talking with friends who have handguns. I plan on shooting my son's Glock 19 and his Springfield XD 45 to get a feel between the 2 calibers. I'm just wondering on other thoughts about these choices.