I am a match shooter, and if I can get the ejector to work I leave it in, because sometimes speed is king. As the old saying goes "If the brass isn't flying your are dying." I will say that if I am having a gun that is having problems ejecting brass, it is much easier and faster to pull the plunger out and pick the brass off the bolt head, than it is chasing the brass around inside the port.

As far as advantage, there is a belief that an ejector can cause accuracy problems as it can tip the case in the chamber as the ejector pushes on one saide of the case. As long as the cases are properly sized this will not be an issue.