I've had the original ZBoard, and I liked it for the most part. My biggest complaint was the ability to type when you had the game keyset installed; extremely difficult at best. Because I got a little upset and set my joystick down on it a bit too hard one too many times, I sort of broke the gaming keyset. With that said, I replaced it with the Merc, which is basically the Fang with full keyboard. I've gotten quite fond of this rather than the original; I do miss the USB hub in the original though.
With that said, if you already have a keyboard you like, but are looking for a gamepad that can give you far better key layout than a conventional keyboard, I think you'll really like it. It was this layout that finally allowed me to use the WASD configuration. Prior to that I was old schooling it with the arrow keys.