Tesla 2019.20.2.1
Release 2019.20.1 is only about a week old, so I haven't yet written about any differences in driving dynamics. I'm not sure what was updated between 2019.20.1 and 2019.20.2.1, having driven each only a short period superficially they feel about the same. 2019.20 generally brings some definite changes to the AutoPilot characteristics. The AutoPilot feels much more bold, it will hold the turns on my normal test route at up to 40 miles-per-hour, whereas I usually dropped the speed to no higher than 25mph; if it loses AutoPilot, it'll still pick-it up in the middle of one of the turns—seems to do this more than under 2019.16.3.2. In what might be a reversion-to-the-norm1, while 2019.16.3.2 brought the car to a stop when it came to a fork in the road, 2019.20 is much more likely to be indecisive, heading in one direction before jolting back into the other direction.
AutoSteer also seems to let-go in less predictable ways now. When I first got the car, I learned to expect that it might throw me into a tree, but now it'll apparently be holding a turn, and then disengage AutoSteer with no advanced warning at the apex, i.e. the point at which it is hardest-to-recover since the car should be turning at that point2. At the same time, the car is still stopping for nothing. I believe it was under 2019.16.3.2 that my Model X, Pensive, started taking a stretch of road that went over I-95 as AutoNavigatable; it wasn't until 2019.20.1 that it decided to turn the wrong way down the exit ramp, which would have brought it going northbound on the southbound side assuming it wouldn't have crashed into any of the cars stopped on the ramp.
While I'm used to losing some charge over time, even while plugged-in since the car won't reinitialize charging if it's only lost a little battery charge and isn't pulling a significant charge actively (e.g. through environment controls), I was surprised that the car stopped charging before the target. I had the battery set to 90% and was messaged that it was complete at only 88%.
Admittedly, I hadn't tried using the environmental controls from the API since I noticed these were broken in 2019.8.5; but these now seem to work reliably again.
In many ways, this feels like 2018.26 again.