So I've had this light for a few months now and overall I'm pretty impressed with it.
Pros: It's a sub $300.00 dollar light if you shop around and then get performance to pricematch it. Run time in the cold(35F) falls to about 3.5hrs versus the advertised 4hrs. In warmer weather 50-60 I have gotten every bit of the 4 hours out of my battery. Charge time has happened in as quick as 3 hours but normally stays around 4 hours. The mounting kit for the handlebar is easy to mount with a 10 degree swivel, it's also durable. The light itself is tough (I flipped my bike on it when I wrecked) and there is plenty of cord from the battery to the light. The velcro strap for the battery is big enough to fit around the beefiest bars. Consider the downtube on my Kona Hoss. The light it produces is well spread and shows you everything you can imagine. Cars even stop for me thinking I am something other than a bicycle.
Cons: The light takes upto 15 seconds to turn on reach full illumination. The light gets extremely hot, and if air does not filter through the light it has turned off. The on/off switch is on the battery which can be a pain to reach if you're trying to turn it on mid ride. The low-battery light is also on the battery, so rarely do you realize it's going dead until it's dead. It has about 15 minutes of light left when you notice the light getting weaker. My only other complaint was no helmet mount, but this issue has been resolved and one has been released.
Overall this is a great light for commuting, trail riding, or liesurely riding. I like it alot and think that I couldn't have found more bang for the buck.