I used a Wacom Graphire Bluetooth tablet as my main pointing device for a couple of years, except when playing games. I only really stopped once I added a third screen which made the tablet impractical to use due to the mapping of the screens to the tablet. I just never got back into the habit of using the tablet as my main pointing device after that.
Nowadays I'm on a MBP and mainly use either the built in touchpad or a Magic Mouse.