The Gopro is great. That being said, there are some obvious draw backs with mounting. The head mount is great for a "POV" dive, however, once you stop moving, the exhaust bubbles tend to obscure the view. Also with the head mount if you are constantly moving your head, so is the camera image and tends to be shaky. Pole mount is good and a variable length pole allows you to adjust to get closer to subject without spooking. There is a new lighting system out for use with the Gopro which is called the Sidekick. It has variable power settings and is 600 lumens at its brightest setting. It offers spot, flood and a combo spot/flood setting. The system comes with two mounting options and for around $150.00 it is a low cost option.
Good luck and happy diving!