By now, my G19 has about 5,000 rounds fired. I just returned from a Masaad Ayoob 4-day class in South Caroline. Two days shooting in the cold rain and mud. Shot about 500 rounds of Blazer 115-gr aluminum. Zero malfunctions and the only brass that hit my head was from the G17 6 feet to my left. Only downside is now, after shooting 1 day with speed reloads, magizines dropping in the mud, I have to clean 26 magazines. Overall, the class was fantastic and I am 100% satisfied with my Gen4 G19.