Using the wrench attack in the air also provides some floating time, much like the Kazooie's flapping in the original two.
And yes, I loved the plane so much more than driving. It was nice ripping around through the sky. I also made a pretty nice minimalist motorcycle that, despite its twin small engines, one small fuel tank and egg gun, gets some very nice speed going.
...This is all based on my messing around in the demo, before anyone asks how I know so much without even opening the game. I might pick it up later, at any rate, when it's on the discounted or preowned wall at around $20. Right now, especially with Sonic Unleashed's drop date imminent, I don't think the game would fare well in my book.