I played with a set of them briefly. The guy who did a 4mm that I beat up all winter is more in the sled world so he is in with the folks at SLP. They come on like what an FMF would and just freight train right up to 9,000 RPM. But the sign off is pretty abrupt. They reminded me of rockets but everything happens about 250-500 RPM sooner. If you are in trails, twisties, and idiot holes, MX, these are for you. But if you wanna be wide open down logging/fire roads, dunes, open gravel pits you honestly might not be to stoked because of the way they sign off.