I have a Hero2. I haven't had any issues with it, with the sole exception being the Wifi Bacpac - it works fine with the remote, but I can't get it to sync on iPhone. So, as mentioned, it's hard to line up shots sometimes. I also have a LCD Bacpac, but then I can't use my Wifi Bacpac. I'll eventually get a newer one.
I also discovered, unfortunately, a good bit of advice with these things. I went snow-machining and skiing for the first time a couple weekends ago. Took the GoPro. But I sealed it at home in Florida. Which means when it got to the colder temps, the air that was sealed inside condensed and fogged the lens. All the vids/pics were no good. So, either re-seal it in the environment you want to be in to balance the humidity in the air, or use special moisture wick things made for the GoPro/case.
Otherwise, I really enjoy these cameras.