Sorry this is long, but the OP asked for a review of sorts, so here we to.
I disagree with those who say the Mavic is "better". It is an apples and oranges comparison. In that regard, this is similar to a BMW vs. a pickup (I have owned both) . Sure with the BMW, it is fast, drives on rails, fun and can park itself, but it is limited to the pavement; but also in speed unless you want a ticket. With a truck, I can hookup my boat, camper, or just load it up to go off road and enjoy the outdoors. And, it still allows me to go on all the roads as the BMW...
Same with the Karma vs. the Mavic. Both travel roads, though the Mavic much better. the Mavic is faster, has autonomous flying with obstacle avoidance, but like the BMW can get you into legal trouble if you let this get away from you be it line of sight, height, etc. Obstacle avoidance is great, but should you really be that close to a tree, person, building, etc? Just fly...
I have a buddy with the Mavic and there is no doubt it is a very nice and stable unit. It does hover dead still where the Karma will float a bit. If you are 75' up and looking down, you won't see it on video, less if looking at the horizon, though focusing on closer subjects can show it as well if windy. The Karma does handle wind well though. The Mavic has a ton of options, that you may or may not use and while it does have more flight paths, I wonder how many will really use them? Like anything, more options may prove a liability and waste.
I would also argue especially with the options, the video of the Karma is better and certainly not a point of contention between the two. You will also never see the rotors on the Karma, where the Mavic has a tendency to catch them. In fact the gimbal on this Karma is amazing. You slam the stick and video does not waver, nor show you blades.
Comparing the two as I said however is really a misguided argument. If we are talking "drone vs. drone", IN the air, I think it is clear that aside from video quality that could be argued either way, the Mavic is a better drone in just about every way including its small size. BUT, for $1000 vs. $400, I would fully expect that... I will explain.
The Mavic is a nice piece of hardware, and if you already have multiple GoPro's, a gimbal, and or plan on doing considerable aerial videography, then it is probably your best option for an additional $1K. if you only want a BMW, or already have a truck and don't care about expense, Mavic is the way to go. Of course like the BMW, you may not need, or really be able to take advantage of that extra speed, so is it really justifiable?
The Karma however at $1100 gives you a Hero5 at $400, a gimbal at $300, then the drone and a case for $400; a pretty good deal. The value and flexibility is unmatched, especially noting the extreme quality of the video you are able to get with the Hero5. If you have a Hero4 or less, you already know the image stabilization while just digital for now on the 5 is still a huge deal. Add to that the gimbal and your video on and off the drone is dead still; amazing really. It is waterproof, so you can take it swimming, boating, diving, you name it. You can take it on land, and with the gimbal, can really get incredible cinematic type shots. This can't be done on the Mavic unless you want to put out an additional $700 plus for the camera, gimbal, micro SD, case for all, etc. I also like that the FOV even at linear is wider than the Mavic. Remember though, linear is only needed if you are looking at the horizon, or far distances. You can widen it up for other compositions...
I have a lot of hours on the Karma and I am still quite happy with it. It really has a bad rap, certainly justifiably BEFORE the recall. Since however it has been months with no Karmas falling from the sky. You still have many complaining of flight issues such as the drone having a mind of it's own, or crashing, but every video I have seen, you can point to inexperience and pilot error from not setting the appropriate return height, to losing line of sight, flying to high in the clouds, etc. Just by watching the videos you pick up many queues of inexperience from having no clue the FAA rules, not registering, or recognizing flight restrictions per location. Really, it comes down to a bunch of knuckleheads that frankly will ruin drone flight for us all because they lack the common sense to read what amounts to a very short and basic manual before putting it in the air. They fail to understand how it reacts under circumstances such as lost controller connection when they fly behind a building, so the drone hovers a moment, then automatically flies to 70' and smashes into a 100' building, landing on a bunch of people? How many errors do we see here and we have not even discussed experience in manual control? Adding no FAA registration and in restricted mode, add 2 more to 3 plus already... I imagine if you need to let the BMW parallel park for you, then whatever, but I prefer to be self sufficient.
Anyway, you just can't beat this for the price. If price is no concern, and you make tons of aerial video, then the Mavic is likely the way to go. But remember, nobody really wants to see continuous aerial video. Like most things in life, and especially videography, less is more. This drone should be used to accentuate your existing video's, not necessarily create 5 minutes of mundane footage that is lost after the novelty is gone. For me, value is still a hurdle that I won't allow myself to get lost in. The GoPro does a phenomenal job as proven by Hollywood. For me, I will gladly take the $700 plus that I would have paid for something of infrequent use, and apply it to another lens for my 7D that will get more usage, get some spare batteries. Or maybe I just apply it to my airfare to Belize. So while ego Tom is getting video of his back yard nobody wants to see, I am getting a nice orbit path over the Great Blue Hole.
All my rant behind me, some main points below as to my experience so far.
Pros
· Flexibility is unmatched; the Hero5 can literally go anywhere, AND look almost of professional quality while doing it. Certainly surpassing the ability of most clods like me.
· Impossibly easy to fly. Extremely stable even in wind, though at 2 lbs that helps. Let off the sticks and it hovers. Very precise movements.
· Auto landing. Depending on the situation, this can/will return to you, return to launch or if you are a really bad pilot, it will land in place because you ran the battery too low for it to return to launch. I have tested multiple situations in letting the battery drain and shutting the controller off while in flight with the Karma operating as designed and returning to launch. I have never had the controller lose connection while flying, heck even when I tried to stuff it deep in my truck during my test it would not lose connection until I finally resorted to powering it off.
· Autopaths. Dronie, cable cam and oribt are used often in Hollywood, and most often in aerial videography. Reveal isn't used quite as much for me and while I would like the addition of others, having these are good. They certainly will help allow even the most novice pilots get outstanding video.
Cons
· Battery: Does this really need to be this big/heavy to hold a Hero5? Maybe. I get that the technology is limited here. Like my 7D, hero3+ and all other photography equipment it is standard to buy spare batteries. It will help ensure you don't push a single battery too far getting that perfect shot. Plan you composition, get it in the air and do your business. Practice before you do this for real, don't waste time at your destination and you will be fine.
· Auto paths. While I like the auto paths it has, it would be nice to add some points to the cable cam. More important than that though would be a follow me feature. The Hero5 has the quality, so no reason this can't be implemented in an update. Fingers crossed.
· Hovering. This is splitting hairs, and only really noticeable at 50' or lower when it is windy. But I do have some shots that could benefit from rock steady hovering like the Mavic has. It's not a deal breaker though and I see more value elsewhere, which is why I have the Karma instead of the Mavic.
· Planning: I would like to be able to plan better, maybe even set points on the controller via map, or better still on a computer. It has maps, so seems like a little programming could aid.
· Tracking: In the event of a crash, loss, or just to show law enforcement in the even some dork claims I was harassing them, or flying in restricted areas, I would like a cookie feature, or at a minimum the last known contact point. Garden variety navigation units have this and GoPro support can access the data, so it should be easy to incorporate for the pilot.
· Sure, I can add to the wish list, but in reality, this is a $400 drone. Can you really expect this technology for that? For that price, the fact that it is in the same conversation as the Mavic is a win. Note I did not say the Phantom 4. Poor video and no portability removes it from my discussion.
Make no mistake, this Karma is the real thing. It easily surpasses many if not all of the phantoms and other drones out there with exception to the Mavic and some of the other high end units. This is not the $600 drone you get without the gimbal, or even some with the gimbal. Right out of the box you CAN get video that surpasses your skill level. It is a stable unit that is easy to fly. As long as you use common sense, this will be a valuable asset.