Scarbo, I ran one of the Soubitez bottom bracket units for about 6 months. It worked very well, at least from a power generating point of view. The downsides were noise, and noticable drag. It sounded like a small electric motor when engaged. Not horrible, but noticeable. As for the drag, I'd guess it knocked about 1 MPH off when cruising. (Maybe 15-20 watts drag). I've since gone to a Shimano 3n80 dynohub, with great results. I can't feel any difference between on and off, so I just run the lights all the time now.