I just plain don't like the GoPro camera format, so I went for the Replay XD1080. Since I've found that my head is rarely facing the same way for more than a few seconds while I ride, which tends to make viewers seasick, I've mounted the cameras on my bike instead.
I would certainly recommend the Replay, with one warning; battery life. They seem to get about an hour and 20 minutes to a charge and, since the battery is integrated, you can't swap it out. They do make cigarette lighter power adapters for them though.
I also like that they have billet aluminum mounts available, and have a couple of them, but they're quite pricey.
Here's an example of what I do with them:
http://www.youtube.com/watch?v=Cx2w9nOtQVM