i talked to Dave Patrick at the Joe Nall fly in this year. He recommended the 1.8 moki over the 2.10 because of the weight. There is a bigger weight difference than there is power. He recommends the servos in the fusalage not the tail for better cg. He says the issue is build as light as possible and it will perform awesome 3d with 1.8. I am going to take his advice and go with 1.8. P.S if you go gas it will void your warranty if you go with the 40cc or the 50's.