ive got his workbook and dvd(an advanced dvd recently came out, which i dont have). its excellent and will help you excel not only at magic, but anything else that you use your hands with. but keep in mind, it will be pretty hard the farther you progress, and very challenging. get it.
Its really great, get it. Along with a hand exerciser and a set of chinese therepy balls, nothing will improve your dexterity faster. as a matter of fact, get all three.