The best Glock trigger upgrade is a case of ammo down range. Break it in and train your finger. This whole topic reminds me of the new AR owner who wants to know what upgrades he can do. Kind of like chroming out our brand new car, buying new wheels and tires, installing a new "bangin'" sound system, a turbo charger, auxillary oil and transmission cooler, Recaro bucket seats and new steering wheel before you even drive it AND, never ever race it.
In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball