Of course you normally use c_trace for FPS, but have a look at the following video (or any space shooter) and tell me how you'd do that with a regular c_trace and particles:
http://www.youtube.com/watch?v=vmWDRlbS6aQ&t=10s


"Falls das Resultat nicht einfach nur dermassen gut aussieht, sollten Sie nochmal von vorn anfangen..." - Manual

Check out my new game: Pogostuck: Rage With Your Friends