Installed 8.5 and took it for a test drive. I gotta admit it's pretty cool. Really the first time I actually felt like FSD (at least on the freeway) is in reach.
Some comments, tho:
1) As someone else already posted it chimes to tell you it wants to change lanes, then it waits a couple seconds and turns on the blinker, then you get the "put your hands on the wheel" notice and flashing blue until you put some torque on the wheel. Until you do it won't change lanes. This actually made me keep my hands on the wheel MORE than when I had to confirm the lane change with the stalk.
2) Lane changes, as in 8.4, are an adventure. Of about a dozen lane changes that it did, it hesitated and took multiple "attempts" before completing the change on like 5 of them. One time it started to change, came back into the lane, started again, came back into the lane, and by the time it tried the 3rd time someone was coming up so fast from behind in the target lane that I had to grab the wheel to stop it from cutting the guy off.
3) In my opinion it changes in front of someone in situations that I wouldn't. I feel it needs to use the rear-facing cameras more to make sure someone isn't approaching from behind in the lane it's switching to.
Anyway - VERY exciting to see the progress!