I used a GoPro snapped into a bracket on the front of the fairing of my first bike, it had a lot of vibration in the image but would have been good enough to prove innocence in a crash. Kind of a pain to mount & power up for each ride.
I have a hardwired camera system in my second bike, with a front and rear camera. It auto-records and has great stable image quality.
I would never ride a motorbike in this country without video for proof when needed.