GoPro makes some incredibly good devices for their intended use: capturing the thrill of sports activities. They are not really a substitute for a good still camera or for your home videos, as some of the design features simply don't work that way. But for virtually any sport, from fly fishing to kayaking to sky diving, they're fabulous.
Some of their software is glitchy. Occasionally their wifi back has a bit of trouble connecting. Some batteries may wear out. But for every "problem" there is a workaround and/or an accessory. And for virtually any way you want to video there is a mount. It's really versatile, takes great wide angle HD videos.
I have the original HD 1080 version. The Hero 2 I've seen does much better and has a bit more functionality, but fits all the same after-market stuff. The 3 is different and better.
If you're in the market for any kind of sports video, you owe it to yourself to evaluate a GoPro. What it captures for me (and for my non-sporting viewers) isn't just the "look" or "view" from your position; it actually captures the feeling of being there. Seriously worth it!