The parts, ammo, and experience most gunsmiths have with modifying a Colt would justify it for competition or duty alone. Not saying a Five seven isn't decent, because frankly I have not a damn clue, I'm just saying if your serious about it then you'll need to seriously familiarize yourself with the weapon of your choice. In English this equates to shoot til your damn hand is about to fall off. Much easier with a gun chambered in one of America's most popular calibers.
When they kick out your front door, how you gonna come. With your hands on your head or on the trigger of your gun?
Guns of Brixton- The Clash