Another thing to consider is the audio recording. Having video evidence of what happened during an incidence is one thing. Recording what was actually said in a conflict may be very important.
Unfortunately, the recordings from the built-in microphones are very weak. And if the camera is in its waterproof case, the audio is even worse. Even GoPro has this problem.
If anybody has used an external microphone or a separate audio recorder, please advise how they turn out. Can they pick up a conversation with someone ten feet away? The other day as I was riding out of a park trail, a lady yelled out from her car that she liked my helmet camera. On the video, you couldn't hear anything that she said.