There are three reasons airfoiled tails are used on real planes. 1)airfoils produce less drag. 2)airfoils produce a greater pressure differential {lift}. 3) the additional thickness allows room for a main spar thick enough to eliminate the need for flying wires. The larger the plane the more effect they have on performance, IMHO it's not likely you will notice any difference in planes under 35%, the reynolds numbers are just too low.