i got one about a year ago as a gift and i'm pretty happy with it, but i didnt expect full on video camera quality anyways...which is good, cos it cant deliver.

i've only used it on public roads and not fast at all but it did the job.
on the plus side its really easy to operate.
the main drawback for me was the lack of a viewfinder and narrow field of vision, so it can be hard to mount for a nice shot. A couple of unsuccessful test runs got me footage of my foot and then of the lane next to me, before i ended up strapping it to the mirror stem, with a strip of rubber underneath to absorb some vibration.
2nd is that it needs alot of light, (eg. not tree cover and shadows at stanwell tops)
and 3rd was the rubbish sound quality.
but it does the job i wanted which was to just record a ride.
so i just watch it with the sound down low, sit around with beers and mates and have a laugh at our total lack of riding skill or style

...that is when they're not disappearing in shadows. hahaha.