Here is my experience having owned this while now with hundreds of flights. Before I start, I received the Hero 3+ as a gift years ago. At the time I thought it was that perfect present since it was a niche/cool thing in action cam I would have never bought myself, but shockingly this is now my primary video camera above my Sony Video Cam and 7D.
At $1100 for the Karma, this is a very good deal and affords flexibility beyond the other drones you see on the shelf at Best Buy. The Hero5 with image stabilization (which is one of the best action cameras out there) is removable, so you are not limited to aerial video unlike DJI, but also add composition on land, water, even underwater to complete your video options. There is also a removable gimbal which when attached to the included Karma Grip, affords amazing image stabilization keeping you composition perfectly level with no bumps, even if you are running, on a bike whatever. The gimbal is the single piece of equipment that will provide the most dramatic change to your video, giving you Hollywood like cinematic shots on and off the drone. Putting a cost to this, you have a Hero 5 for $400, a gimbal for $300, which puts the drone cost with case at $400. It is not just this flexibility, but also the total cost that should be considered when comparing drones as most comparisons to the Karma are not apples to apples. How can it be, they are limited in capturing video in the air, with less quality optics than the Hero5... Regardless, for $400, this Karma will fly circles around any other drone even at twice the cost. To introduce a Mavic Pro into a true comparison would mean $1900 for the extra equipment already included in the Karma (I also added a 2nd Micro SD since you would not use the same one for both). BTW, if you already have a GoPro, even better as you have massive mounting options already.
Speaking to my experience thus far, this drone has been pretty incredible. It is very easy to fly, so much so that my 10 year old takes over the reins when I need to be in the shot be it driving the boat, etc. It is very stable, even having a learning mode until you get acclimated with the sticks. It is more than impressive in the wind it handles; I would say I have flown it in 30MPH winds and it still provided very good video. This was testing, which BTW I recommend as well. If you view YouTube, you will see many crashes, even people blaming the Karma, but looking at the video's, 9 out of 10 are user error, irresponsibility or just not knowing the limits or how to fly; often many mistakes at once. So, they fly it behind a building or mountain, which you should not do and lose sight of the drone, the drone loses connection and when it attempts to return, it crashes because the pilot did not set a return flight, or even know what it was. Again, hundreds of flights here and I have had no issues, have not crashed it, or even been close once. Like a car, you pay attention, and you don't need a sensor to apply the brakes for you... Actual Video of the Karma is better than the Mavic and has more flexibility in composition in the air, not just on the ground. The point; this drone will take equal and better video than the Mavic will, and that is ultimately what it is for.
I recommend that everyone research prior to buying any drone and be realistic in what you want, vs. options. The Karma does not have sensors, so there is no true "autonomous" flight, to which another drone, the Mavic Pro does have. These sensors afford the Mavic the ability to work with GPS to provide perfect hovering and obstacle avoidance. If you research, you find these sensor do not always work and will not avoid items like trees, bushes, power lines/poles, etc.
To my point of testing, I take this to a very large open desert area to practice not just the auto path features, but also what could happen in a bad situation. I tested the loss of controller connection to the drone by powering it off while the drone was in flight. I also ignored the warnings and allowed the batter to drain where the drone forced an automatic return. Return to launch and return to you were tested and it always acted as designed bring it a few feet to my landing site. Keep in mind that even in these automatic return modes, you can take over control to get it on that pie plate if need be. I also tested distance; again to 2500' at a max of 400' high. Not once has the controller lost connectivity and doing this gave me immense confidence in the drone.
I also continue to test autopaths and different manual composition, so just like the safety aspect, I know what to expect and won't freak out, but equally as important to ensure when I really want video, I know what to do and am quite efficient than just flying around and wasting battery. BTW, like any camera or electronic device, buy a backup battery. It will also help promote safe flying where you don't put yourself in the position of a drained battery after you have already ignored warnings.
Back to research. There are drones that claim farther limits than the Karma, however the FAA restrictions affords a 400' ceiling, and line of sight. In distance, that translates to 3000' max since the drone is a black dot. This distance is well within the Karma's capability, but some like the spec of a 3 mile drone. BTW, you also have to register this drone with the FAA, so it's best to research your limitations there as well before you buy (Part 107).