The P90 is a blast to shoot, well with free ammo, full auto and 50round mags it sure was.
Ignoring the debated terminal effects they are a bullet hose, reliable, compact, accurate, no climb, very little recoil. With a can they feel like a supped up airsoft gun.
If ammo drops to .223 prices and becomes available I will buy one in a heart beat, then I can try to figure out how to carry the stupid mags.