Btw, most of those that know how to view and read data from the flight log files pretty much knows what they're going to see when comparing your new & old aircraft files.
This also is the very reason why I no longer update firmware and currently use version 1.4.1 firmware. Dji became determined to program the Smart Batteries to not last as long thus needing replaced sooner. In the process of doing this the aircraft began shutting down in flight dropping from the sky. This took place when the battery Volts dropped to a critical level. Even more so, cold weather effects volts in the battery even faster so the number of aircraft crashing were out of control. As a fix, dji programmed the aircraft firmware so it would not fly as fast and not be so Volt Dependent as it had been prior to the crashes. The result has been any aircraft with firmware above version 1.5.7 flies slower, especially under 70 degrees.
Now recently more pilots are starting to mention their aircraft is slower when descending. This is a result of those who have complained about how fast their aircraft was descending. Some occasionally said their aircraft was wobbling and almost violent enough to possibly crash when landing. There was also a small group complaining the aircraft would land too fast while using the auto-land feature in the app. They said the aircraft would hit the landing area so hard that it would bounce and tip over. SOOoooo.....rather then just programming the aircraft to slow it's descent speed to a set amount of feet from landing, then just reduced the entire descent speed.
If there is something you don't think that gets changed, there is only one thing or way that I have ever known to work and that is by a large number of you to post in dji's forum asking for a change. The more that post, then better the chance the engineer tech's will get the message and there be a possible revision. A post here and there on this website is only wasted effort.