The answer to that AllModesR/C is really dependent on the plane. Some planes, probably most planes, need a little bit of rudder held during the turns to be coordinated properly due to the adverse yaw effect of the ailerons. You can trim out adverse yaw with aileron differential, but for many aerobatic and sport planes that will give you proverse yaw in vertical lines which most of us find more difficult to compensate for. Planes that are particularly prone to adverse yaw (like Cubs) will look better in a turn if the rudder is applied at the same time that ailerons are and held in the whole time, while planes that aren't so prone to it will turn just fine with a little bit of rudder added during the aileron deflection and then stopped once the plane is banked and you've stopped using the ailerons.