Going on 1500 rounds through my Gen 4 G17 without an issue. Both my Gen 4's have been solid from day one. I rank them up there with my old Gen 2 G21.
-Glocks: Gen 4 G17/G19/G42; Gen 3 Zev Tech G17/Vickers Tactical FDE RTF2 G19
-Sigs, HK, Walther, Springfield...etc, etc