I've been reacreating the laser dance scene (Ocean's 12) for a project. So far it looks great, I used the lightsaber emmiter, and Elvis Dean's Laserline. I managed to get good beam movements, different sizes for different depths of field, nice surface bounces, and even a great flare for when the beam crosses the camera lense.
What I couldn't get, is a perspective beam change. one that starts small (in size) at the source in the background, and large at the foreground.
Very tough to do. You may be able to fake it by animating "zoom" over a few frames and if the emitter uses "emit at points". Takes a lot of tweaking though, since you have to make sure that the particles only get added once along the line (and don't cycle over again at the start of the line). If you do it right you'll get small particles at one of the line, and larger particles at the other end.