There is a difference in the way the two planes fly by design. The Edge is better at tumbling and it's stalls are far more aggressive than the Extra. The Extra flies a better groove and is much smoother to control inputs, this makes the plane present itself better. The Extra is also not as likley to wing rock in elevators or harriers and all this assumes a similar set-up on both planes. The one that is best for 3-D is the one YOU are the most comfortable with, they are both great flying aircraft.