All I can say is, WOW! The light output is astounding; with essentially the same LED as my previous battery lamp, this thing lights up the road far and wide with a bright and relatively even illumination, clearly showing every nook and cranny of LA's shattered streets. Almost all the light goes down onto the road in a well-defined long rectangle, with plenty of side coverage into areas where you are likely to turn.
My other lamps have sent a lot of lumens up into the trees, where they didn't really do me much good. Bless those German government regulations!
Basically, every lamp I've had before, including super-bright ones, is a piece of crap next to this. And the Cyo isn't even B&M's best lamp.
I had Gina ride up ahead at one point to report on how it looked from in front, and she said that it was highly noticeable, but that she was surprised to find that it didn't blind her. (Those German regulations again.)
The SP hub, which felt typically notchy in the hand, spins freely when built into a wheel. I don't really notice any drag. My concern is the rather narrow 50mm flange spacing. I've heard good reports from previous users, but will evaluate it again after five or six thousand miles.
I'll post a more detailed review on the main site here after many more rides and miles, but for now I feel as though this was money really well spent. I love riding at night; I hate being unable to see the road while worrying about when my battery will die.
I got the Cyo R version, slightly less bright than the N but with better illumination right in front of the bike, necessary here in Pothole City.