You can see the original review at SevenDayCyclist
The K-Lite Bikepacker Ultra Dynamo Light produces a maximum of 1300lumens at 17mph and comes in both road/gravel and Snow/MTB versions. I've been lucky enough to play with both and frankly, they're like having a premium quality 1300lumen light with unlimited run times. Fully water and shockproof, they're phenomenally rugged, too.
Pros: Beautiful build quality throughout , phenomenal performance.
Cons: Completely sealed, non-serviceable components. However reckoned to last ten years.
HAND BUILT TITANIUM FRAMES.