My buddy has been on a Glock buying spree lately, he just bought a 19 and a 21sf, he already has a 1st generation 17. He put a 3 1/2 lb. trigger connector in the 17 and 19. It made a big difference in the trigger pull. I would not want it in a defense situation, but really like the triggers for targets. He doesn't shoot as good as me so he is always asking me to shoot his pistols to try them out ( which I enjoy ). My range pistol is a DW PM9, I am more accurate with it than any of my other pistol, except maybe my 686. I shoot it better than his 17 or 19, but I contribute it to me being use to my pistol not that they are not accurate. Well today I shot his 21sf at the end of the session. We had already shot his 17, 19 and my Kahr P9, I didn't bring the DW today, didn't feel like cleaning 2 pistols today. His 21sf surprised me and him with how accurate I was with it. I thought that I was good with my 9's, but I have never shot a pistol better than this one. After we finished shooting it, I pulled the slide off to check for trigger bar wear, there was no wear at all and the pistol was flawless. I was very impressed with my buddy's Glock 21sf and a little frustrated that I paid so much money for my TRP.