I've owned a 6X8 wacom tablet for about 3 years and hardly ever used it. Mainly because I rarely freehand things directly on the computer.
Now if you do photoshop/painter painting or want to get that handdrawn look then go for it. I usually sketch out my ideas on paper, then use them for reference. But I create all my vector artwork by using the pen tool for the most part.
If you can see yourself using it often then buy it, they work great. But I hardly ever had a use for it because I don't do much "traditional" artwork on the computer.