By "trust" do you mean 100%? If so, I do not trust AP at that figure. Maybe 75%. TACC is wonderful. I use it most days on my commute to work. Never thought it was that useful until I accepted the AP free trial (did not initially purchase it). Use it both on freeways and city streets, even though it's not recommended there. Auto-steer (AS), on the other hand, is not totally baked yet. While AS works well even in inclement weather, by that I mean the recent rains we've had here in NorCal, it totally depends on (seeing) the lane markings to do its job. I've used it on long stretches of highway driving in the #1 lane in good weather but beyond that, I'm not trusting it. One minor complaint I have about it is that it always tries to maintain the car in the center of the lane. While that's certainly a basic and important feature to have, I like to hug the left side of the lane when commute traffic goes below about 50MPH as that gives motorcycles more room to pass safely. Above 50MPH or so, if they are crazy enough to want to lane-split with minimal spacing between rows of traffic, that's on their head. If there was an AS option to prefer the left side of the lane when the speed goes below a certain threshold, my "trust" of AP would increase slightly (albeit after a long amount of time testing it).
Note that my impressions are coming from software 28.1. Recent updates may have changed the performance of AP but I'm not there yet.