They've been playing with these plasma flashlights for a few years now, and they are still struggling with stability at temp. Cold conditions affect the plasma just like fluorescent bulbs. Great if it's 80 degrees out, not so good if it's 40 or lower. The exciter voltage needed really strains the supply system in cold weather.

Also, don't expect plasma to hold up mechanically nearly as well as LEDs can. Plasma is better than incandescent, but I am spoiled on being able to drop my flashlight 4 feet to the concrete floor and still have it go.

Plasma does have it's prospects though. If they can get the price to something reasonable I might have to get one some day.
I do see the next generation of LED flashlights is at 100+ lumens finally. I doubt plasma will be able to compete economically with that for a long time, even if they can cut the power consumption by more than half.