Magic shine MJ 872 - 1600 lumens - bought mine 3.5 years ago and it's been superb. Mostly used on its lowest setting, even on unlit roads, but occasionally gets switched on to mid setting for short stretches of road.
A single charge usually sees me through a week of commuting, each run being a minimum of 45 minutes, but I usually extend that on the way in to work.
The only problem I found with mine was the cheap plastic parts of the frame mounting kit, but I now have the battery contained in a chopped down water bottle in my front bottle cage.
There has been no drop off in the battery performance, despite the many charges over the years.
I think there may be a newer model available, which will be worth considering if it's anything like the older one.