Im a 2 stroke fan, the 140 rx's we are running on coolpower 5% nitro, hattori pipes... thats cheap running as the rule is, the more nitro you use the more money its gunna suck! For bang for your buck I dont think you can beat the 2 stokes.. Its all just an opinion though, really they are all capable of the job, its just down to what youve had experience with...