I have a waccom. It came with photoshop elements and corel paint.
I haven't had any issues with it, and it works well in GIMP. I didn't buy it myself, it was a gift, so unfortunately I can't put any input on that matter.
I'd listen to waffle, test the waters first, then upgrade. I know you probably don't want to shell out 100-150 at first especially if you are going to upgrade, but it's better than putting all of your money in someting you won't ever use.