The Sig Akromaster was my choice to use to learn the AMA stunt pattern back when the beginner class was still required to fly the entire schedule of maneuvers. It was powered by a Fox 15 and still managed to complete everything including the hourglass and clover. The one modification I made was to add working flaps. I'm sure this helped improve it's ability to get thru the pattern. With a modern OS 15, it should do remarkably well. Over the years my kids and I have built maybe a half dozen or so of these and have not had a bad one in the group. All but one has been crashed into nonexistence or passed on to other flyers.