And....
I'm waiting for those caveats...........
I own two complete 3DR Solo setups, and just bought a Mavic Pro with 4 batteries and a lot of extras on eBay a few weeks ago.
My experiences so far...
I fly the Mavic in Sport mode much of the time - this disables the collision avoidance. I do this because the collision avoidance causes the Mavic to stop or behave oddly when flying into the sun in the morning or evening. The collision avoidance does not work with small tree branches in front, and definitely not to the sides or rear. For me, it has not kicked in even once - except for one time when I tested it by trying to slowly fly into a large obstacle. I think that small tree branches are the most likely obstacle that drones collide with.
One of the main things I like about the Mavic vs. the Solo is the more precise position holding - especially at low altitude. This is because of the optical flow sensors on the Mavic. The Solo has the possibility of getting optical flow also (it has firmware support), but it will be a fairly expensive add-on.
The other thing I like about the Mavic is the range. The range is fantastic - but only when using the DJI Go 4 app. For some reason that I have not been able to figure out - the video range is TERRIBLE when using Litchi. Constant video freezes if I try to fly more than 1/4 to 1/2 mile away. The Solo actually does much better. (especially with the upgraded WiFi cards I put into one of my Solos)
But using DJI GO 4, I can fly a couple of miles with clear like-of-sight. Awesome! But, very disappointed with Litchi so far.
So, why am I trying to use LItchi?
I bought Litchi because I wanted to use the Litchi mission hub to fly pre-programmed missions. I really like flying pre-programmed missions and was using the Tower and the missions add-on to Solex with my Solo's. DJI GO 4 does not support preprogrammed missions. Litchi mission hub seems very powerful, but I really feel uneasy about flying the missions in Litchi when I'm getting video lock-ups so readily. I'm really hoping I can figure this out because longer pre-programmed missions was one of the major reasons why I added the Mavic to my fleet.
I still love the 3DR Solo. It handles the wind better and the Solo app and Solex aren't constantly nagging you about updating firmware. The video from both drones is very good, but the Mavic gimbal is smoother - especially when flying fast. The Solo gimbal is crippled by an overly stiff HDMI cable.
It's very hard to find spare Solo parts now, but you can still buy new Solo smart batteries at $30 a pop. I only wish Mavic batteries (which are much smaller) were as inexpensive.