I've got several of these around the house, great beater lights with awsom output for the price. I've given a few away as gifts. My step-dad, who used it every day in a "heavy abuse" type work situation, did manage to destroy it after about 6 months. But in that whole 6 months, he never had to change the batteries, lol.
The weak points of these lights is the switches, and the threads, both are pretty poor quality. But these are heatsinked so well, that they can be driven hard (and ARE), I've measured nearly 5 watts to the LED on a fresh set of NIMH off the charger. no problems with the LEDs in any of them so far.