I´ll just throw in my 2 cents worth. I go along with Chunkylad: control set up is just as important as engine sellection. I have a Desire 60, powered by 2 stroke OS 91FX, as my practise plane. I use JR 4131 coreless servos (on 6 volts), carbon rods and Dubro screw horns. As the man said, sealing those control surface hinge gaps makes does make all the difference. My 2 metre planes are great but a lightweight, well trimmed 60-90 sized plane is a joy to fly and still competitive up to advanced class.