If you check out that review it shows that the product definitely needs to mature. I can't see the wacom one being used for professional purposes until they up the accuracy. I was going to buy one for my finance for her birthday (she has a cintiq but wanted something for the go) but decided it wasn't worth it.
On top of that inkling requires that device to help read from the paper which limits its usefulness some (for me at least).
Hopefully they improve on it because it's definitely an interesting approach to this problem.