I downloaded 7.0 in Columbus, OH and immediately began a road trip to Florida. I used AP extensively on the trip but was always paranoid about problems. Here is my trip report:
Life with Autopilot: 1500 miles trip report
Every update is like that, and 8.0 is not different. If we carefully remember that this is NOT AUTONOMOUS DRIVING and pay attention at all times it is hard not to love it!
Sorry about shouting.
By reference I am an Airline transport Pilot and Flight Instructor. As a pilot I understand what an autopilot is, an aide, very excellent aide, but aide. There is no substitute for paying attention. Not doing so can kill people, and does. The recent Emirates Boeing 777-300 crash at Dubai (first hull loss in Emirates history) is an excellent case in point because the pilots were being complacent so tried to take off without adding power. Pretty stupid, and those guys will probably not fly again anytime soon.
The Tesla crashes are, it seems, all of the same type as that 777 crash.
Most of the complaints about AP in updates are ones that are seemingly expecting Autopilot to be something it is not.
Most of the complaints about software updates seem to be made by people who have not studied the release notes nor experimented.
It is not all perfect at Tesla, they make mistakes, but I find, after almost two years, that Tesla updates are better than Apple, my previous stellar example. I have not yet had an update that caused any problems and I do not personally know anyone who has had any problems.
In sum, don't worry about. Enjoy. Study the upgrade notes, be mildly irritated that minor updates do not come with notes, then join the threads here where we figure those together. Soon it becomes fun, especially the Cowbells.