I have to disagree on this, I don't see the point in having more than one media player embedded in boxee. While I understand the frustration of poor performance at the moment, I still think the devs need to fix the issues and not focus on adding another layer.
BTW, I would be really curious to see the how well an external player would run with boxee running at the same time, considering how much boxee takes in terms of resources. You can actually do that using Fuzz's launcher! You can try: add vlc to Fuzz's launcher, launch it, open a video file and try to watch.
Just remember that there is boxee box coming out by the end of the year, so I am almost sure things will be fixed real soon
All my computers are Ubuntu-powered, so step aside if you don't want to be run over