I use this to commute 32 miles a day to and from work year round in the midwest. I primarily use the blinking feature to alert drivers then go to the solid light once it's dark. I don't use the full power function much to conserve battery life and find that most of the time I have enough power to get to and from work. I charge it pretty regularly and haven't seen it quit during a ride yet. I've been using it for about 6 months and it was a significant step up from my previous cheaper light.
Bought this light for commuting during the winter months on a route that has a fair amount of dark sections and it simply works for that purpose. The amber side lights are a nice safety touch and the "shimmer and flash" mode attracts drivers' attention and is easier on my eyes than a traditional Flash mode. Battery runs down pretty quickly in the highest steady light level but the light is so powerful that one of the lower levels lights the roadway well and saves power.
I ride day and night. Daytime - plenty bright to be seen. Nighttime - I can see! Easy re-charge. Easy on/off. My only beef with most lights is that they don't last as long as claimed. That's why I always bring a spare when the weather is super cold or I'm going to be out near the time limit it says it will last.
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.