My second season of Shimano dynohub with Lumitec 3 watt light. Works fine for my somewhat hilly suburban 30 mi RT commute, I have streetlights along most of my route. Mainly need the light to be seen by oncoming cars, but occasionally I ride on an unlit MUP with no problems. I use a couple of battery powered blinkies on the back. The time difference in my one hour each way ride with light on or off is almost too insignificant to measure, compared to my regular hub that I put on from April to September. One or two minutes difference at most, don't really notice.