I bought a Contour HD and wasnt impressed. At the time the iPhone app didnt allow you to start and stop recording. It appears they've added that function in the +2. The aviator lens kit that comes with the NFlight version of the camera is just a tint to darken the image. When the camera compensates with longer exposure the prop wont show in the image as often, it does tend to blur the image more if theres any vibration.
Check out the Drift Ghost. I have a Drift HD and I love it. The remote has a long enough range to start and stop recording with the camera on a wingtip or the vertical stab. The Wifi in the new Ghost will get you further, and the smartphone app will let you view in real time. Waterproof to 3m, andstreamlined (I used the 3M adhesive pad they supplied up to 230KIAS and I still have my camera) . A 32GB card will outlast the battery. If you dont need the wifi, the HD will still shoot the same quality video for half the price.