On the Surface side, there's Gabe from Penny Arcade, who's kind of informally become their artist advocate. If the Pencil's fidelity is as good as the Surface's

On the Surface side, there's Gabe from Penny Arcade, who's kind of informally become their artist advocate. If the Pencil's fidelity is as good as the Surface's -- and I wouldn't expect it not to be -- it seems like it would be perfectly capable. That said, the Surface also works because it can run full versions of programs like Photoshop. I don't know how that plays out on iOS.