I use drones for work (VIDEO), and I also have the Mini 3 pro. With 360 degree sensors, the new active track, HDR video, and 120 frames slo-mo, this drone is a lot more complete than the mini 3 pro. Unfortunately, ND filters are currently as rare as a unicorn in my backyard, so I'm forced to continue flying with my Mini 3 for a while.
The new active track is quite useful, but to be honest I wouldn't blindly rely on it. Maybe it will get better with a new firmware update, but at the moment, flying between trees, for example, is quite a challenge for the drone - the chance of a crash is very high! With a bit of luck the drone will remain intact, but who knows, it might end up hanging in a tree somewhere and you'll be the target. I would say, consider a care refresh subscription if you plan to use the activetrack often, because one day that drone will certainly take a nosedive.
By the way, with a care refresh subscription you will have to hand in the drone, so falling into the water or hanging from a tree means setting up a recovery operation :-)
For those looking to switch from the Mini 3 to the Mini 4, please note that only the propellers and batteries are compatible. The rest, like the controller, ND filters, and the storage case, are like apples and oranges - they just don't fit together. And let's talk about those batteries. The Mini 3 batteries are 4 grams heavier than those of the Mini 4. Do you notice that difference? No, probably not. But your drone is now officially too heavy to fall into the "lighter than 250 grams" category. Theoretically, because who would ever stand next to you with a scale when you're flying?
But despite all this craziness, this really is the best mini drone you can buy.
