The audio pickup, compared to my gopro hero (1), is significantly better.. i do not know if the new gopro has fixed it audio, i'm sure it has though. The AS20 has similar mounting options to the gopro, I actually made a custom mount based off of this video: He is using the AS15 in the video
I use the 120 degree view, the 170 is just too distorted even in the gopro, which is why i also went with the sony because of its 120 degree angle. The 170 degree view with the sony doesn't support its Steady Shot technology but the 120 does. The 170 is overkill it just looks unreal, its not POV.