I've been using the SP 3.5 for about 4 months now. Never been opened up and still performs. It pulled away from a sponsored LRP driver using the new LRP 4.0. Massive amount of power, but as Besercoe said, it's quite thirsty. Making 5 minutes requires the absolute newest batteries if you have an aggressive driving style. And yeah, the sound is out of this world, sounds like a F1 engine on steriods
