Which compact drone should you get? It is really exciting to have two options and I honestly think both are great choices but there will probably be one that is "more right" for you than the other depending on what you are trying to do. I wanted to get my thoughts out there to help you decide. Did I miss anything?
GoPro Karma - The Karma is larger and not as advanced as the Mavic. DJI has done a good job of making the Mavic look better in every regard when it comes to specs but I don't think this tells the entire story. The appeal of the Karma is that it is a little film making backpack. It uses a GoPro so you can swim it in and under water. It has a steady cam in the backpack for super smooth hand held shots. Lastly, it flies the GoPro. It is an all in one solution and I have always been attracted to simple and this small backpack is all self contained. I also LOVE that you do not have to use your phone for the video downlink because the Karma has an all in one controller. When you are going around filming, the less stuff you need to bring along the better.
DJI Mavic Pro - Tiny, obstacle avoidance, long range, object tracking. Lots of killer features. The 4k video I have seen from this is not that good when compared to the Phantom and Inspire. This thing is tiny and folds up into a tiny little package. If you don't mind bringing along another camera for ground shots, this is an extremely convenient way to get aerial shots.
Aerial clips without ground shots or other types of shots has gotten a bit boring because things have gotten so easy. My goal going forward is to start bringing different kinds of shots to make my videos more interesting so the GoPro Karma represents the easiest way to do this with the backpack. If all I wanted to do was shoot aerials, the Mavic would be the better choice if I did not mind the video quality issues.