Very stable tripods.
I haven't completely verified this yet, but I remember reading somewhere that tripods are not to be used -possibly even due to a certain CDRH regulation.
Personally, I'd never use them anyway as there are too many variables like people bumping into them or bass vibrations. Scaffolding all the way. I also like flying truss, but only for smaller lasers or perhaps a fiber-fed projector.
-Jonathan