Performance and durability has been excellent. As a veteran wildlife biologist I depend on my equipment to support my livelihood and my safety. I've been using this headlamp for everyday night use as well as for calling for owls. Owl surveys consist of hiking out across the landscape in steep walked canyons and forested landscapes to designated routes and stations along the routes in southern Utah, Arizona and New Mexico. Calling occurs from dusk to almost dawn. I carry a spare battery but have not had to use it yet, I've found battery life to be excellent. The headlamp is rugged as I have had it torn off my head by tree and shrub limbs, had it tumble down slickrock canyons, it still worked without issue. I don't find this unit is so heavy that it pulls my hat down in front, or gives me headaches from the weight or from tightening it down so it won't come off or move. This is an issue I've had with other headlamps. The "boa style" headband ratchet it great, superior in fact. I can sinch it down snug so it stays put, unless I walk into a tree or shrub limb and rip it off. I appreciate the various settings, and the independent buttons for spot and wide beam. I used my headlamp on all of my hunts this past year, but using it in Alaska on my dall sheep hunt was a lifesaver. After harvesting a ram we ended up hiking out when it was dark through some treacherous steep, losses rock areas and it performed flawlessly. I appreciated the high lumen output and battery life. Durability and waterproof qualities are unmatched. I highly recommend this company and this specific model to anyone who would have similar needs and functional requirements as I do. I have not found any dislikes yet. It is worth the price, I go through a lot of headlamps for work, and I can tell already that this one is going to be with me for some time.