I took a three-day pistol course this past weekend at Defensive Tactical Institute near West Union, Ohio. A great experience, but more about that later. I decided to run the entire weekend with my ever-so-slightly tweeked Gen4 Glock19. It has a cleaned up trigger pull, Ghost connector, and Trijicons front and rear. It has been equipped with the Glock-provided replacement RSA. I no longer run it with a Crimson Trace because left-handed carry doesn't work well with it. The gun had about six thousand trouble-free rounds through it prior to the class.
During each day of the class, I fired between 400 and 600 rounds. I fired as few as one round per exercise segment to as many as sixty. Each night, I did a field-strip cleaning on it. I fired from a variety of stances, angles and distances. I experienced exactly zero malfunctions over the entire weekend. I enjoyed a perfectly flawless performance from a gun I had already come to have complete, unqualified confidence in.
As an aside, never reholster into an IWB after you have run three quick mags through your hi-cap gun. It gets warm.