First use occured on a pre-dawn group ride. I attached this light to my handlebars because it was advertised as slightly brighter than my existing light and motion urban 900 whose battery life was starting to decline. Well, this one is a bit brighter, but less waterproof. On the return leg of the 50 some miles in damp conditions it was flickering on and off. When I arrived home I found moisture had gotten inside the lens. Will be returning/exercising the warranty.
I only road bike during daylight so can't comment on this light's nighttime performance. For safety using slow flash mode this light works well. Quality is very solid. I own four Light and Motion head lights and am pleased with all of them. Easy on off handlebar rubber strap mount is very secure. Battery life is good and recharges easily.