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.
-Glock Gen 4 G17/G19; Gen 3 G17
-Sig P226 Navy/220 Elite/M11-A1D/1911 TACOPS/M400
-XDM 45/Walther PPX M1