What should be really worth is ability to draw directly on the screen (not very cheap). I tried a small tablet and finally switched to inked drawings (when you scannerize a ink draw it is just matters of adjusting contrast to get edges for easy digital colorization, with pencil you can instead have all sort of troubles).

With my 8 years of experience drawing with a tablet, I'm pretty confident with my hand eye coordination and muscle memory for this task, but I doubt I would have the same luck playing with it as I do with the track pad or a DDR mat. ;)
I think of it as eating soup with a fork. Right tool for the right job and all that.

I could probably benefit from some drawing from the elbow practice, though.

Throw away your mouse.
Seriously, I've not used one for 10+ years... for anything at all (I'm an Art Director and concept/game artist btw).

Wacom ftw!