In reply to mypyrex:
Like any bit of tech or camera equipment they are a compromise.
which model were you thinking of getting (the line up has just been updated)
there's a new basic model which will be about £120 apparently
the gopro is popular becase the market well and their cameras are generally quite good (they've had some firmware issues in the past, but they seem to be on top of that now) they pay attention to the mounting options (i suspect that's where they make most of their money actually)
you need spare batteries and decent memory card (the cheap and cheerful cards may not work, but you can quite safely use none std batteries) and you may need to spend a bit more for different attachments (the handlebar mount for example can be attached to your walking pole and used as an extender pole)
there's a great forum for gopro users here
http://goprouser.freeforums.org/
oh and if you have a smart phone (apple or android) you can control most of their modern cameras from the phone. i used mine recently at a wedding as wide view fo the church and being able to control it from across the room from my phone was invaluable)