I have a camera & rear facing camera on my bike. It does work - and is surprisingly resilient in all weathers. It also has that 'wow' factor. However, there are a couple of things to be mindful of:
1. the focal length of the camera. Mine shows everything in a wide screen (I guess for parking etc) so makes everything look far away. This is very different to a mirror which is easier to gauge the distance of rear objects.
2. Mounting the camera. Vibrations can make the camera quite shaky so placement needs to be considered. Another thing re placement would be to mount it under something / in between something so that rain doesn't blur the lens.
A couple of things I would do if I updated my set-up would be:
1. a switchable lens / two lens system so you can have a wide / close view
2. rig it to a recorder so you can record rides - much like a dash cam.
3. Also mount a discrete front mounted cam - switchable of course
I also mounted a single rizoma bar end mirror in addition to the camera - for piece of mind.
Hope this helps