The brightness and variable output is extremely good and easy to use. The form factor could be better. Very heavy - I added a strap across the top scavenged from another headlamp to stabilize, which helped a lot. I would prefer a lighter high strength plastic housing - like some of the Surefire (nylon or polypropylene) flashlights. The small protective cap over the charging port is too flimsy and easily knocked out. Finally, I would make the battery pack flatter and wider so it rests against the head or helmet rather than the current design that sticks out and easily hits things. Battery life is excellent though. Comes with car and AC chargers, which is good but expected for the high price.