I haven't used it myself, but I've worked with a few people over the years that have. They swear by it... especially the SpacePilot. I'm happy enough just using my wacom though.
Are you using a cintiq 12 or 21 inch. On my cintiq 12wx the Wacom Tablet Properties (Accessed through the start menu) allows me to edit the function of all the keys.
Anyone feel like giving this a try and see if they can recreate it? Try vertexpainting on a mesh with your wacom. If i use a mouse it´s ok. As soon as the pen touches the tablet it crashes instantly.