I just purchased a Drift HD Ghost on ebay from the US (still in transit) and a few suitable camera mounts, audio patch cable etc from Camzilla in NSW (very good to deal with). I did a fair bit of research and it was a contest between Go Pro, Drift, Nflightcam and contour (seems to be the same as Nflightcam). The GoPro would appear to have the best pic quality, but the others are still pretty good, good enough for my means.
Overall, for me, the Drift Ghost has the best package of features ie water proof to 3 M, or in my case shower proof if mounted on the aircraft externally, as it is out of the box and no need for a waterproof case, remote controlled, 2" LCD screen to easily see what you are framing up, 5 minute loop and tag feature, the longest battery life of all of them, can be mounted at any angle with the rotating lens.
I plan to mount mine on the top of my vert fin for starters, will let you know how it goes.