My wife has a 2018 XC 60 with the new version of Pilot Assist. I have only driven it once, about 200km of highway driving both divided and undivided highway. I found it to be quite good at lane-holding, with few disengagements. The cruise was fine at holding distance to the vehicle in front. It needed constant attention though, there is a very very short window where it wants to know that you're holding the wheel - like less than 30 seconds if I recall correctly. It also found it was not always easy to know when it was disengaged or about to disengage. I wasn't worried about the safety though, it performed quite well.
Although I don't have Autopilot on my car, I recently had a 2018 100D with AP2 and tried it out briefly on a drive of about 60 km. Same divided and undivided highway. The Autopilot did just as good a job of staying in lanes and holding the center of the lane as the Volvo system, but Autopilot had fewer nags about wheel-holding and the IC display makes it easy to know what the car is seeing and whether it's currently in control or not. Overall I would say that the Autopilot implementation gave me more confidence that the car was managing the road, but once I was used to the Pilot Assist I was quite impressed.
Very limited experience with both for me, but I hope it is helpful. I'm quite impressed with the XC60 overall, too bad it's not electric yet. A BEV version of that car (with a charging infrastructure) would be pretty much ideal for me.