Well, it's not supposed to be a primary trainer, but I'm using my Hobby Shack Super Sport Trainer .40 on the buddy cord, and I love it. Fast, tracks like it's on rails, good in the wind and goes where it's pointed. The K&B .61 gives unlimited vertical, and it is very aerobatic. I've been flying motor gliders prior to this, so sort of started a little ahead of the normal learning curve.