I have one.

Pluses: Cheap, small. Mounted on my handlebars, people have no idea it is a camera. It looks like a light. You can select from 2 different frame rates, and 3 different resolutions.

Minuses: Mounted on handlebars, it picks up a lot of vibration in the image. The vibration conducts through the mount and case and drowns out any other audio. I haven't tried helmet mounting, but I suspect that would be better.

It is designed to be water-resistant. On a forum somewhere I saw a posting from a cop who opened it up and removed the waterproofing protection from the microphone. He said it made a *huge* improvement in the audio. The cop was using it mounted on his person to record traffic stops.