My dyno-powered light was the weakest in the B&M product line for its year. Somebody tried to argue in favor of replacing that light with a more powerful B&M, but I liked the idea of having two lights instead of one - the weaker light for "see me" duty, and the stronger one on my helmet - it has a flash mode too.

There's one section of the Mt. Vernon Trail that gets dark as hell at night - really glad to have the two lights when I'm riding through it.