Yes I have risked the life of my Trio for the sake of science... it becomes insanely bright... I mean seriously the brightest I've ever seen from 5mm. But.... highly highly highly not recommended as you will burn out the leds rather quickly. They are already being overdriven as is, so with the lithiums they won't last very long... i tried mine only for about 30 seconds or so before I chickened out.
I have lithiums in mine and so far no problems. I checked Gerber's website and they said lithiums were OK in all their lights except the LX3.0. It is damn bright for only 3 leds. It is possible that the light is overdriven and it might die an early death.