First 10.12.2 drive:
tl;dr: Welcome refinements but more work to be done.
Tested in rush hour traffic, for a extra-special experience!
More assertive at intersections. Generally, it does a good job taking its turn correctly and moving out confidently. But, not always. Still seems to hesitate a bit or start out slowly at some intersections. On the whole, however, it is much improved here.
Turns are smoother than ever. Like with stop signs, there still are some turns that result in some steering jerkiness. Mostly on turns that are unusual in some way. I had one unprotected left where the car turned toward the oncoming lane on the left!
Seems to do better staying in the lane on tight turns, so long as they are not too tight. I had one case where there was a sharp, 15 mph, turn where the car did not slow down enough and ended up halfway in the opposing lane. No oncoming traffic, fortunately.
The car still slows down too much when the car in front slows and turns right. Then, the car hesitates and does not accelerate quickly enough to recover. This has been a problem for a while and has not improved.
I had one case where the car pulled into a left turn lane when it should have continued straight. This is another nasty habit carried over from the previous version.
I got two cases of the mysterious three-beep warning. Both seemed to be on curves with oncoming traffic, so maybe a brief FCW? No message on the display. The car did not otherwise react and kept driving fine. Annoying.
A couple very minor PB events that seemed to be in response to oncoming traffic on two lane roads. Neither case was concerning at all, but noted. Will need to drive more high-speed two-lane roads for a better test.
No Red Wheels of Death, despite driving on unlined rural and residential roads.