This just happens to be the ongoing discussion in the iPhone gaming community: does the bigger screen warrant for my expensive prices? Most iPad games don't even do anything other than resizing the graphics and making them look all pretty on the iPad. But like I said before, other than that, the iPad versions are the same thing as the iPhone version.
And that brings me to Touchgrind HD: what's so different about it? The iPad version has the same whatever and whatnot on there as the iPhone version for $7.99 versus the $4.99 price tag on the iPhone.
And while some may view it in that way, I view it in this way: bigger screen equals enhanced gameplay. The bigger screen does wonders for Touchgrind, including the ability to see obstacles easier and pull off a skateboarding move with much more ease than the small iPhone screen. There's also the ability to do split screen multiplayer against your friends and family, bringing the multiplayer experience to the max.