Been using mech. retracts in different planes for yearswith very few problems. Flying a 15 yr. old EZ Zero and the retracts have never been out of the plane. Once in a while the gear will bend back in a less than perfect landing, but the legs are flexible enough that they will bend if they wont fit in the holes. Turn the plane upside down , bend them forward again and away you go. Retract servo runs off the rcvr, batt. Circuit in a proper retract servo shuts off at the end of its travel so there is no servo drain. You aren't going to experience the ins and outs and foibles of retract if you don't try it. Better to try them in a fourstar than a perfect scale model