I have one...yeah, they are fun for about 3 minutes...then the charge runs out. It woulda been better if I could read Japanese, woulda made building the thing easier. Still not sure if I did it right...works most of the time, every once and a while I hafta bump it along. But it's fun to play with when yer bored waiting in line or something like that. Not quite as powerful as my boss's RS4, but hey, I can still dream.