I've owned the Contour Roam, still have a Hero 3 white, and also the Sony ActionCam and a few other no-name cameras.

Currently I run a pair ofRD32IIs, which is a Chinese camera that sells for about $125. I actually like it better than either the Contour or the GoPro. In my tests it has been better able to produce readable license plate images than any of the other cameras I've owned. It's enough cheaper that I was able to afford two, front and rear facing. I can really not tell much difference between any of them as far as video quality goes, until you start looking at still frames.

Once you're at still frame, it goes like this:
RD32II is the best, pretty clear stills
GoPro is next, only a little worse than the RD32II
Contour is a bit more muddy in still frame than the GoPro.
The Sony is abysmal in still - the frames are extremely muddy, they look like a copy of the video instead of the original.

The RD32II also does not have an easily replaceable battery, but it's just a common 3.7 volt LiIon cell and from the teardowns I've seen it looks like anything vaguely the right size would work as a replacement, there's plenty of room in there. From what I've read, the Contour is very difficult to open and close and still have it be waterproof (in fact the docs that came with mine basically said that if you opened it, you'd probably never get it waterproof again, so best to send it to the factory for battery replacement).

I do 90 minutes of recording a day on both cameras. I think if I was still using the Contour, I'd be very close to 500 charge cycles because I'd have had it over a year by now.

If you're choosing between the Contour and the GoPro, IMO the factors are: the Contour mounts a little easier and looks slightly less idiotic than the GoPro on a helmet. The GoPro has a replaceable battery (aftermarket batteries and chargers are cheap on eBay - I did this and $20 got me two batteries and a charger), and with the GoPro you can do almost anything to settings, erasing the card, etc from the buttons on the camera. On the Contour, you have to attach it to a computer to do ANYTHING - change resolution, erase files, set the time/date, etc. With the RD32II you can change things from the camera but you have to attach it to a monitor first (has both composite and HDMI outputs).