I've been flying RC for 9 years, and have used Great Planes EZ connectors on every servo of every airplane I have built. I have never had a failure.

I fly .60-sized airplanes, Top Flite fighters for the most part.

I use them because they are the easiest to adjust. I tighten the bejeebies out of them, and check them before each flight and have yet to experience any ez-connector related failure. In fact, I've piled a few in (my fault) and the connectors held even after the jolt of a nose in crash.