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!