Hi Guys - it's apples and pears really. If you want to record shooting footage, then the GoPro is perfectly acceptable. If you want to understand your shooting then ShotKam is more suited, as the footage is specifically looking at where the actual shot corresponds what is aimed at. The reticule(s) superimposed on the footage give clear guidance as to what is right or wrong in the shot.
Mounting any camera on a shotgun is not easy, and the stresses from the recoil can quickly turn a £145 camera into a £0 doorstop (as developer David Stewart found out to his cost).
What happens with the ShotKam is that after switching it on (in the field), the video is activated by (for example) the gun being locked, whereupon it starts to capture film. When the shot is taken, the ShotKam takes a predetermined clip of the footage from before and after the actual shot(s). You can adapt the settings according to what un, type of shooting, choke etc)
If I'm not mistaken Phil Coley also markets "Shotseer" on his website (priced £1495), though I havent seen one directly. I am sure that is also a far more sophisticated gun camera, that you can't really compare to GoPro. I like GoPro cameras by the way, I think they are excellent value, but not really a training tool.
Martin
ShotKam UK