I have used expo on mine with great sucess. I put my stick at half throttle and adjust the expo to get the engine to run a little over half of max rpm. I use this as a starting point but it is usally close for me. This way I can fly and 3D my Extra with the stick mostly around the center. This with a DA 50 by the way. Works for me. Others use a point adjust to set 3 or 5 different rpms from idle to full bore. Use the functions in your radio to make the throttle react the way you want. The aircraft will be more fun to fly....