OK, got 20.10 and FSD 12.5 today, less than 2 days after getting 20.9. Naturally I took the car on my usual 5-mile test loop to Subway. The loop goes surface streets on the way there, and it takes the freeway back, so I see city and highway stacks.
First Impressions
-smoother! Speeding up (little), slowing down (sometimes a lot) and going around curves (nice). Meaning it still takes off pretty fast, but smoother. Slowing for lights is a lot better, and sometimes it just creeps up, waiting for it to change. Curves seem to be blended into the straights better, as if the car is looking a little further ahead, and acceleration through curves is very smooth.
-stop signs - still slow, but if there is a turn following, it's much more assertive and quick to turn. No more of this endless creeping into the middle of the road before deciding there really aren't any cars coming.
-no hands! I did the entire 10 mile loop without touching the wheel or either pedal
-ASSO - unchanged. On one 40mph road I was doing 48 with cars around, but soon thereafter only 39 with no cars around
-my community gate - coming back it nailed it! I have it programmed to open as I approach, and before the car would freak out and try to turn around before the (slow) gate opened. Now it drove right to the gate, waited until it stopped moving, then went though. Definite improvement.
-It ignored one yellow light and basically ran a red. Technically the car was in the intersection, but just barely. Never tried to slow down or speed up with the yellow, but it had plenty of time to stop. I guess this is more human-like, but a human would have gassed it a bit in that situation. I was very surprised.
-No change at all on I-17. Still the V11 highway stack. Still won't use the HOV lane.
It will take me a while to get used to the no hands/no nag. I'm used to just hooking one hand on the wheel. Not that I can't still do that.
In my test, there aren't that many challenges, but 12.5 took what 12.3.6 did OK and did it better. Sometimes dramatically so. I doubt the drivers around me thought a human wasn't driving the car.
Why did I get this update? Well, I'm driving a HW4 Model Y, I've got a subscription to FSD, and I have Advanced selected under Software in the main menu. I didn't even have to wait for 24 hours since my last update check - Tesla pushed this one to me.