I have a ‘23 SR+, the phantom braking is real, and happens frequently- but you can usually tell when you are in conditions that cause it and prepare accordingly once you get used to it. Other vehicles I have owned,
Toyota Tacoma for example, did the same thing.
The standard AP is awful at highway speeds compared to other vehicles I have had, namely our previous VW Atlas Cross Sport and current Volvo XC90. That being said, it doesn’t jerk the car around if you are changing lanes without signaling, etc, like many other vehicles do, which I like.
I do find the AP useful in heavier traffic that is not full stop and go- provided you don’t mind having cars dive bomb the gap between you and the car ahead.
That being said, the car is a wonderful commuter, and I love it. I prefer to drive without AP, using only the CC when the roads are relatively empty. We are three weeks into ownership, around 2000 miles total. My wife and I work opposite schedules so she drives it to work at night and I use it during the day, saving the wear and tear, and cost of fuel on our other vehicles.