Did some FSD 10.8 testing today:
Left and right turns at intersections were noticeably smoother. Not sure why this has been so hard to implement, as Tesla certainly should know their cars' turning dynamics. But, progress here is welcome. Having the steering wheel swing wildly back and forth during a simple 90 deg turn was annoying.
Stop signs were horrible. Most cases, the car took far to long to decide that the way was clear. A few cases were OK, but generally not. I have seen little evidence that the car can reliably determine when it's turn to proceed has come. If there are two other cars at the intersection of a four way stop, the Tesla almost always will just sit there until I use the accelerator to proceed. This even on the assertive setting.
Unprotected left, and often right turns are poor. Often, the car will just sit there. At one right turn, the car displayed "waiting for high speed traffic to clear" even though there were no cars to be seen in either direction.
Phantom braking was improved for me. I had no issues in town. Out of town, on FSD, was also very good. One incident where the car crested a hill with a right hand curve immediately following and an approaching car rounding that curve resulted in the Tesla screaming bloody murder and hitting the brakes. I'll consider that an edge case.
I tried checking phantom braking on two lane high speed roads on NOA. I didn't have any incidents, but I only had about 10 miles. It seemed like the car wanted to use FSD on more rural roads than before, but maybe a false impression.
On FSD, the car seems to wait until the last minute to switch to a turning lane. I've had more than one case where the car skated across two lanes to dive into a turn lane. I have to admit that acting so human-like put a smile on my face. But I would rather it plan a little further ahead.
The car still takes reduced speed turns too fast on high speed two lane roads. This is especially evident on right hand curves. The car does slow down prior to the curve, but the car gets too close to the double-yellow line. The lines have reflectors embedded in the road and I can feel the tires rolling over them. I know it's a performance car, but Tesla needs to reduce the lateral g-limit for these turns a little bit.
On rural low speed roads with no centerline, the car tends to position itself toward the center of the road. If there is an approaching car ahead, the Tesla does move toward the right, but it waits too long to do so. Also, on these roads, the car tended to reduce its speed below the posted speed limit (29 mph vs posted 35 mph) with no notification.
I find need to disengage FSD when approaching any rural railroad crossing unless I know that it's a smooth crossing. the car does not recognize the need to slow down for a rough crossing. I also had one case where a railroad crossing was very close to a stop sign. The car slowed for the stop sign and made its initial stop without fully clearing the tracks. That's a major fail.
"The Love Car soon will be making another run..." 
