Review from
Cycling Weekly
The whole system is expensive. On the other hand here is a light that runs almost forever, pumps out a serious beam, tells you when the battery is low and tells you when it is recharged. It is incredibly light, unobtrusive in use, and generally well made. Assuming USE sticks to the same battery format for a while, it is possible that spare battery prices will come down as lithium-ion technology develops.
In conclusion...
Most road cyclists will regard the Exposure light as an expensive luxury; those who really need a top quality light however, may view it very differently.
Rating: 9/10