We have a hero 2 and use it extensively on our bikes during races with no real issues. I do have two comments if you are considering this camera. Do not get it if capturing sound is important. The mic is not that powerful and if you are using the full sealed case even worse. Most people edit the videos with background music. This is a camera to capture action when handling the camera at the same time is not an option. Also, all the settings are via toggling the settings/options button. I could see this leading to issues for those who do not like to review or keep the manual as it is easy to mess up the settings making changes.
So my take is, if you are using it for the intended purpose it is a very good camera.