Got a chance to ride pro-am's boost it viper and all I gotta say is WOW!! I can't wait to get my sled this fall after riding Chris's sled. Going to hook up with NM tomorrow and ride his sled, but these boost it vipers at 8-9 pds will outrun my mcx 270 kit on my nytro. the throttle response is absolutely night and day compared to my nytro. NM has done a bang up job on this setup.