I have also been thinking about the same thing. I currently use the GoPro H3 on a pole mount to a Ram ball and Yakattack track mount.
With the pole: you will get quite a lot of sound transmitted up the pole from the kayak. You hear every bang from the pedals or paddle, clunk as you pick up a rod from the rod holder, bump and any sound through the kayak, kind of like you are bumping around inside a big plastic box.
I will still continue to use the pole mount but also intend to bea able to utilise the GoPro quick disconnect mount clip and swap from pole, to chest strap or head strap mount.
See the pole mount behind in the photo.