I've been using my Magicshine for over 2 years now. I've had to replace the Y cable 3 times now, but they're less than 2 bucks each. I have their taillight as well, no problems.
However, if doing it over now, I'd use a pair of UltraFire flashlights up front and a Cygolite Hotshot and some other light in the back. I would only use one of the front lights at a time but I always want backup, I don't care if it's a $1000 light, it can fail, and I HAVE been stuck 4 miles from nowhere on a road full of potholes in pitch black with 2 hours until dawn. Lemme tell ya, it's no fun trying to ride by the light of a PBSF on steady mode held in your hand.
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Work: the 8 hours that separates bike rides.