I had B... I paid $50.... It stopped working after a few months (motor controller wasn't beefy enough). It was fun
Eventually I'll put the new controller in it
A nice feature of the old controller was that it PWM'd up to speed when you hit the button - no need for hand control.
I've seen a few (like the ones you posted) on campus... And one nasty crash. Skateboard wheels don't car if it's electric - cracks eat 'em up :/