I use AP every time I’m on the highway and it works quite well in most scenarios for me in Massachusetts. I don’t use it in the snow FWIW.
The longest stretch I’ve used EAP for is >3 hrs going from MA to NY. Highways were totally smooth, did its own lane changes, etc.
It can be slightly jerky at times when the traffic keeps speeding up and slowing down sharply, that’s my only real complaint.