I had a AP2? 2017 Model X with FSD for a few days and the NOA was definitely interesting but ultimately not very useful. Lane changing needed my input and was so slow as to be essentially dangerous.
I guess you have not used a version from last month or so then?
I just did 2 stints covering around 225 miles, most of which was on NoA in very busy conditions, my longest continuous runs so far - M3/M25/M40 and M56/M6/M42/M40 (so Birmingham). I didn't use AP/NoA on M25 or M6 roadworks (but used TACC on latter as we were running with a massive Hermes lorry that was too big for comfort in the lanes). 4 disengagements, one the car was probably at its lateral limit (M56/M6 merge), 2 were aborted lane changes where I unintentionally took over and final one was off ramp flare (single split into 2) which I have come to expect. Whilst I had a hand full of reluctant/refused lane changes, all were obvious why - majority were that it seems that it will delay a lane change until it is sure you are holding the wheel (like a nag but without the nag), so a light wiggle of wheel allows it to complete (it becomes instinctive after a short while) and I think 3 were down to cars suddenly coming out from behind and either overtaking (it actually pulled out but didn't pass), or heading for off ramp. I didn't do M25 as when joining from M3, my lane was to merge with M25 and I was running parallel with a lorry - I didn't know how it was going to react, so I played cautions and took over and due to nose to weight of traffic, didn't go back to NoA until M40.
Other than that, and not being speed limit or corner speed aware (M56/M6), it worked very well, no hesitation, no get half way and timeout etc.
My only criticisms, which passenger also mentioned, were that on aborted lane change, the indicator stops so when second attempt is made, its probably confused the car behind with second set of indicating. And my continued biggest criticism, not handling lane flares.
I also witnessed TACC for extended periods, as driver (M6 roadworks) and passenger (M40) and it worked flawlessly. SWMBO on M40 had no issues of hesitation when overtaking (something that put her off before and others also mention on here) and was very impressed (she is a bad passenger and even worse driver when not in control of the car) when in stop start traffic. She was not sure if smoother overtaking was due to leaving a bit more room when pulling out.
Would be interested to know what other peoples experiences are with TACC overtaking on latest software releases.