If you are already a good player (say B or above), there is no substitute for the experience and knowledge you get from playing a top player. It's one thing to see great pool played, and it's another to have great pool played on you. When you FEEL what's being done to you, and when you experience the penalties that can be imposed for adequate instead of excellent play (like playing merely a good safety instead of a lock-up safety), a tremendous amount of learning and inspiration will the result. Just observing the focus, demeanor, and rhythm of a top player can help to bring about a quantum leap in your game.
Great offer, Larry! 'Nuff Respect!