My favorite (and first) Glock, a G19.4, it has Ameriglo Agents, a Glockmeister Grip Plug and a Tau SCD. Bought it the year they were released. Had a low single digit number of failures, took it by the Glock mothership as a walk in around 2010-2011ish and they installed the new Gen 4 specific ejector and RSA, had zero issues after that. It’s had several thousand rounds through it, the majority of them for three of the four years I was a Cadet on the West Point Combat Weapons Team. Pic bonus: my favorite rifle, an LMT CQB.