I have never messed with one.....this is my first. If I did proms and bigger school activities, I would probably get more. The problem is the venues and haze/fog.....if you cant use haze or fog, I would totally pass on getting any type of laser!
Slightly off subject, but the schools around here are clueless when it comes to raising money through dances. They typically do free dances, and some local dj's will show up with some beat up mtx or peavey boxes on sticks, with 100 cds, and a vertigo, for $150. The only exception to this is a prom or formal, when they hire a different guy with more stuff, but for about $250.