Get the Glock.
Cheaper to shoot = more shooting = you'll be a better shooter. Placement is EVERYTHING.
Cheaper gun means more practice ammo, right? See above.
Lighter + more compact + more shots = better for defense (all service-grade handguns are pathetic in power; .45 vs. 9mm = 10,007 vs. 10,003 angels dancing on the head of a pin).
Accuracy? A box-stock G19 with decent ammo vs. an unmodified rack-grade-quality 1911 with same decent ammo? The G19 will usually win (90-95% of the time). Might win by a LOT, depending on the exact 1911 and the shooters' experience.
The low bore axis of the Glock means less muzzle flip; this makes no difference for the first shot, but can be a BIG difference for subsequent shots. If you can shoot the 1911 well (speed & accuracy), you'll shoot a G19 superbly, given some practice. The muzzle-flip thing is not caliber-dependent; I've shot these base gun models with the calibers reversed (G30 in .45 vs. a 9mm 1911) and the Glock was still quicker for followup shots, even though it was much lighter and harder-kicking.
Finally, many 1911 shooters I know tend to baby their guns. They hate to get them scratched or holster-worn. Most Glock owners don't suffer from gotta-keep-it-nice-looking syndrome. Glocks are ugly to begin with, and a few scars or wear marks just improves their character.
"Placement is power" -- seen in an article by Stephen A. Camp
(RIP, Mr. Camp; you will be remembered, and missed)