As a Yamaha 9000 Pro user and veteran player, I agree with Dreamer's statements totally. The functionality and pro-usefulness of the 9000 Pro is what earned it the "pro" name. My keyboard has been fully expanded up to 208 notes of polyphony, which is actually a rarity in the professional boards. That plus it's six assignable audio outputs makes it especially useful in the studio when laying down sequence tracks. Before the 9000 Pro I only played heavy Kurzweils on stage, but they now rest comfortably at home and the 9000 Pro is my primary stage instrument.

But beyond all that, these days so much so-called music is done with programs like Acid and Fruity Loops which require no musical skill at all, yet produce hit records. Arranger keyboards can do similar things but actually require the input of a musician to work. And certainly if you go beyond the preset patterns into your own realms of original arrangements then today's pro arrangers are every bit as expressive and professionally-useful as any other keyboard on the market bar none. You really owe it to yourself to learn more about them.