The Pro clubs do not impart as much backspin on the ball as the Master clubs. The ball flight trajectory is a little bit higher on the Master clubs. Finally, the Pro clubs are more tolerant of swing path and tempo errors. As an experiment, I played my first round today using Pro clubs and I was surprised at how much easier it was to keep them in play and stay more on target. The Master clubs simply give me a more dynamic challenge, one that feels more like the innate difficulty of the real game.