I'm definitely impressed with the improved auto lane changes in 40.2.1. Driving on AP, I was able to "cut in" in some busy traffic using the stalk to initiate an auto lane change and it worked beautifully. In the past, the auto lane change would have taken too long. I do feel like this more assertive auto lane change is a key prerequisite for city driving since being able to make those quick lane changes in busy traffic is very important in city driving. AP finally has auto lane changes that I feel have a chance at working in city driving.
NOA auto lane changes are great but still suffer a bit from that delay if you get the steering wheel nag. If you have one hand on the wheel, exerting the right amount of torque, the car won't nag you and the auto lane changes in NOA are assertive and confident but if you don't satisfy the torque requirement, it will of course nag you before executing the auto lane change. In my experience, the auto lane changes in NOA are very reliable now. Hopefully, we are closer to true "no confirmation" auto lane changes in NOA soon because I really wish we did not have the nag before every auto lane change.