Reviewed by iRunFar.
I've got one of these. It's real nice aside from the lack of a replaceable battery. If you're looking for a lamp that you can recharge on a long over-night run, for instance, this is not for you. Also, if you're looking for a dedicated trail-running light, you might want one that's a bit brighter.
But if you run at night occasionally, mostly on the road, as I do, you'll never regret this purchase.
I used it for the Reach the Beach relay race, and it worked perfectly.