I guess the points to consider here is that the servo is trying to control a much larger flap than a Q40 and the elevon is in the middle of the turbulent prop blast. The Q-40 guys who would use the H 5125 [flat wing servo] for roll control only, aren't asking as much from them as this delta will, so it looks like either the H5955 TGS or the JR DS8611 will get the nod.