Just one more thing to add here, I'm one of those who has no issues disabling and re-enabling FSD when I forsee difficult situations arise. And in some drives, it happens often. Kinda preventative, rather than reactive (which I'm sure most will find it most stressful). It has now become a second nature. When there are less cars around, or no cars following me, I let it do what it wants to do, and report if needed. This probably has something to do with my 90% stress reduction.Very true. And this is why I think Elon is doing himself and Tesla a disservice by hyping up FSD so much. By definition, it is going to not live up to the hype.
For the record, my own expectations are fairly low. Back in late 2017 / early 2018 when I ordered my car, there were quite a few people ordering FSD (at the then even high price of $8000 or $9000), but I figured it still had many years to go before it was ready for prime time, and that I would upgrade later if it looked close. I did buy EAP under the mistaken impression that I could summon the car into my garage to charge it (something it still can't do today, even with the simple "just back up" summon), and because I did want the ability to change lanes with my turn signal--it was a bit more than I thought it was worth, but I figured I was investing in FSD development (at that time, Tesla was not in the strong financial position it is today). When there was a $2K FSD fire sale, I did grab it then because I figured it would never be that cheap again.
I am reasonably happy with what I would call enhanced autopilot behavior, although in some ways, I think it has taken some steps backwards since I first got it. They finally did improve handling unmarked merge lanes a release or two ago, but beyond that, it's quirky behavior regarding lane changes (even though I manually select Minimal Lane Changes every drive), unnecessary slow downs (not phantom brakes per se), and refusal to change lanes at times, I long for the days when it was just a bit "dumber".
Around town, FSD is really impressive where it's good. But it also has some things that it just can't handle. So I feel that I probably have to pay more active attention than if I was just manually driving the car, so there is no way I can claim a 90% reduction in stress (maybe it's even an increase). I will say I had a recent success: I went to pick up dinner for my son & daughter-in-law and she ordered a drink that came in a humongous cup (I think it was actually a re-purposed togo container). It would not fit in the cup holder. So I held the cup in one hand, and used FSD to drive me home so it could so most of the steering (I still had my free hand on the wheel ready to take over if need be, but it would not have been easy to take 90 degree turns with one hand). It did just fine in the 3 mile trip through their area.
On the highway though, it's really good, except that I have to hover my foot over the accelerator in case I get a braking event.
So I'm not using it the way Elon wants me to use, but I don't care, this method works for me.