A friend of mine has a Contour camera, and he mounts it to his bike helmet for cyclocross races. We were just talking about it vs. a GoPro. GoPro certainly has the brand recognition and mind-share right now. But we think it's kind of a crappy form factor, all boxy and blocky, with a separate waterproof box to put it in. I mean, why not make the whole gizmo waterproof, if you're just going to have a waterproof box for it? All that being said, it does get great results, and you know popular reality shows like Axe Men, Gold Rush, and Deadliest Catch are using them all the time.
In my opinion, the best finished video results are all about editing. Raw footage from one of these things is a yawn-fest. But good editing makes all the difference in the world. Just remember, it takes like 10X or more the amount of time to make a good video… You want a cool 15 minute video? Got a day's worth of footage? And 10 hours to edit it all down to 15 minutes? I learned this from a friend of mine. He took 3 day's worth of skiing helmet cam video and edited it down to a "Ski Weekend" movie trailer style movie for us… And then never had the time to make the actual "feature film" of the weekend!