
I have 2 GoPro line mounts... and they both have their faults. I wouldn't recommend either. The camrig is on the left with the GoPro in it and a DKS dan kite mount on right.
Here's the + & -.
The DKS holds camera upright and is less tangly. It has has wider arms meaning it can go higher up lines which suits my bar kite set up. (Ozone). It holds in place with wedges and your flagging line can run freely. The things I don't like are it's heavier & bulkier than the camrig with more wind resistance. It is cut out of hard plastic which could chaff lines especially with the way it wedges. Also the hard plastic makes them more susceptible to vibration, however this is negated with new GoPro session with image stabilisation. The red twist mount screw needs to be replaced with Phillips head to avoid tangles.
The camrig is their universal model. I'm surprised they haven't come up with a new one that holds the camera between the lines. It has its faults but I prefer it because it is low profile, light and has the least wind resistance. You can feel them in your lines and are better off using them slightly overpowered. Although fiddly the rubber grommets dampen vibration and hold the camera securely. You can see by above pic I have cut one green rubber wedge down on flagging line side and deepened groove underneath slightly so it holds but easily flags if needed. I have removed back wedge. With all these mounts you are better off getting assisted launch and land. It has narrower arms but I place it higher than I should raising my vee in fronts. Slightly higher gets a better frame and keeps camera drier. Because it is smoothly moduled and rubber mounted it is line friendly to wear. I've never had to come in but do pull my steering line from around it occasionally.
They are not just for the hero shot but a good tool to see your errors. It's interesting to see how often you are disconnected from your board you are at times, and recovery. They do however give a distorted image on edges of frame.