go go 4xTesla guns! It doesn't use mana until you hit aliens or destructible's Mad amount of ammo and chains to other aliens.
The only way a competitive game of Alien Swarm would work is if it was set to insane difficulty and to measure the times taken to complete each mission.Tier 1 of the competition would be the first stage, tier 2 the second etc.This would require 2 things, a sourceTV slot on a Alien Swarm and a SourceMOD that unlocks everything for everyone or something similair.The higher level people always have the advantage, so it would never be a fair competition so you need to figure out a way to unlock everything for everyone.
But you'll always get people new to it wanting to play etc, so it would never be fair without unlocks, so we'd have to restrict it to default weapons only or figure out a way to give everyone everything via sourcemod plugin of somekind (if sourcemod works)
I'll be in for a bit o' this. I've found the damge multiplyer most usefull too! Also, lots of xp available on insane.