the two are exactly the same except for a red wheel and a black metal back plate. 🙂
EDIT: i should also point out that i've had my U2 iPod for nearly 6 months now, and there is no scratching on the front, and only half a dozen hairline scratches on the back. I have a feeling that they may have used a different coating material on the U2 iPods, but i can't confirm this. You may not even need the Invisible Shield. Just use it with the included case for a while and see how you go.