Re: wind noise
My SD had mechanical noise. It was the smallest bit of movement in the shutter button, but when you put it on a V-Twin motorbike, it wailed and was very overpowering. Might be something similar? Or definitely wind?
Ended up sending it back and they either re-furbed or replaced it. Either way, it doesn't do it now, and the HD certainly doesn't.
The instant record can save a LOT of frustration.
Like having your best session on the track and finding out later that you took a still shot in the pits :|
If it is 'instant on', it uses the default profile (for me is video), and starts recording straight away = less angry me.
I think they also did some work to remove the bright (black) spot from the sun. Or was that the HD in general?
I also like in HD that the video isn't as wide - gives a better idea of depth.
BTW: It's under 100 MPH that they suggest using the open back cover.