I think it's crap. There is a test on a norwegian site, a seller got bored with it all over facebook sales threads. This seller got a light lab so he tested its real output and it was peaking at 513 lumens. After 45 min 413 lumen, after 80 min 50 lumen.
Ui is crap. Fist click is center led, next click is side leds, next is all tree, next is strobe, then finally off. To turn off the light you got to cycle trough all modes.
Lots of pastic, and feels uncomfy on the head, because of the hard plastic. Heatsinking, well, lol is all im going to say.