Todd Green at Pistol-training.com posted about his experiment with reducing Glock trigger pull by using aftermarket parts. Glock factory settings tend to be around 6-7lbs despite what Glock claims.
Todd Green used APEX Tactical, Taran Tactical parts. Some other people shared their measurement with ZEV parts as well
http://pistol-training.com/archives/9504
From: Pistol-Training.com