I have an iPad and an iPod Touch right now, and in the next month or two I'll be getting an iPhone 4. I'm looking at buying N.O.V.A., but I'm debating which version to buy. On the one hand, the iPhone version will work on all of my devices, albeit with lower res graphics on iPad. On the other hand, I can get gorgeous full screen graphics on the iPad, at the sacrifice of compatibility with my other iOS devices. Which do you guys recommend? Does the iPad version have any other bonuses to justify the lack of compatibility and higher cost?