i have a Wacom intuos 3 and to be honest most of the time I unplug it from the pc.
It's great if you draw and make textures but as a navigation device I find it horrendous and it interferes at times with my mouse hence the unplugging.
I wouldn't use it to model in Maya as it can be really awkward and it's far easier with a mouse.

To sum up you can't beat it in a paint program but it's not really any help in a 3D package or certainly no advantage.If you have the money and like to create 2D or need to make textures then go for it, but otherwise it's just a luxury you won't miss.