Interesting feedback. Was this mostly on divided highway?
My results are the practically the opposite. I feel like 17.4.14 is where I was 2-3 versions ago, as far as reacting to turns and staying between the lines, on undivided highways and country backroads. I know that is not the Tesla recommended use case, but I drive a route everyday that has become my baseline for testing AP. For example, there is set of 90 degree turns, smooth and level with clear lines, one 15mph the other 25mph. On 7.1, the car would not slow down at all into the turn, definitely would have run off the road if I did not take over. Early 8.0 releases I noticed it slowed down for one turn, but only in one direction. It wouldn't stay between the lines, but would at least stay on the road and recover. Later releases got progressively better, through 2.52.22, which would navigate both turns in both directions, albeit a bit sketchy, but the turn 7.1 almost handled was doable completely between the lines no intervention. I hoped with 17.x it would handle both turns completely.
But no. Now, the car is trying to kill me again. Barely stays on the road in that turn, and doesn't even attempt to slow down on the other one. I am hoping this is just a case of one step back, and we'll see an upcoming 2 steps forward!
On the freeway, things are great. But they have been for a while.
My ultrasonic arches do seem to extend further now, and the reaction time to move over when paralleling a wall is almost instant now, whereas before it would see it, but response was slow, if at all. I'll take that improvement!
As for the Dolby setting, mine turned off with the upgrade, but after turning it back on seemed to stick.
Haven't noticed much else yet, but looking forward to the future!