I've seen both the Mavic and the Karma, and I have to say they hit different use cases.

The GoPro is for when you want a drone that can carry your camera that you can also detach and use with their stabilized handle, which you can then take the GoPro out of completely and use on it's own.

The Mavic is for people who want a smaller drone.

Both are good tech, and I plan on getting both of them within the next year, but the GoPro one is going to be my first of the two.