I'm not going to add much more than has already been said, but I just want to simplify your choice. This beats GoPro in sound quality, low light image quality, image stabilization, and price. The watch is a fun addition, but anyone with a smartphone can save their money and opt out.

GoPro wins in diving depth, and marginally in image sharpness.

If you only need the sharpest image with the option of diving to 200ft, and those are worth $120.00 more to you, go with GoPro. If you also require great sound, in-camera stabilization, and good low light performance, and don't care about diving or a tiny loss in sharpness, and want to save some money to boot, this is the camera for you.