Here is what I posted on our local group's Facebook page.
Good morning Tesla friends! Just got back from a short drive to try out the new 8.5 Nav on Autopilot update. Short response...this seems to be a fully function complete FSD for highway use. Very impressed. That said, some very interesting observations.
First some background. I was on the highway in moderate traffic with light rain (but with the spray from the traffic I am sure the system thought it was much heavier). I had the driver acknowledge turn lane turned off and the turn lane notification set to both wheel vibration and chime. In the future I will probably turn off the chime but each to his/her own. I also set it to automatically default to "no acknowledgement on each trip' so any time I put in a destination it will automatically go to these settings. There are other options.
First off, it seems the system would not engage without first acknowledging the driver presence, aka torque on the wheel. It wouldn't engage for me the first time I tried for this reason and gave me a red prompt to put my hands on the wheel. Very smart I think.
Next, the on ramp performance seems MUCH more confident. My exit is a two lane on ramp and it smoothly accelerated and moved over one lane then did the same to enter the highway flow of traffic. MUCH BETTER!
Next thing I noticed was that it seems to require the same "driver presence" verification before performing any lane changes. In other words, it would signal but would not move over until my hands were on the wheel. Again, I think this is very smart on Tesla's part. Keeps people from abusing the system I think.
Next thing I noticed was that it appears to be more sensitive to poor weather. It went from Nav on Autopilot to regular Autopilot three times during my trip for this reason. Each time it would re-engage when the rain let up or when traffic cleared out and there wasn't as much spray. Lane changes were all smooth and confident. It would wait for an opening and then smoothly accelerate into the new lane. It would then return to the right lane to get out of the passing lane much more readily I think than before.
Overall, on this short trip, I was blown away. Can't wait to try it on dry roads and a longer trip. Sorry for the lenghy post but thought some of you might be interested. Of course, everyone will have different opinions, but I think this is a BIG step forward for the system. Can't wait to see what Hardware v.3 has to offer when the time comes.
Hope that helps.