I took advantage of the one-month trial of FSD that ended, for me, in May. Having only done the trial, my experiences will not be as complete as those here who are using FSD on a constant basis. That said, my experiences during the trial did not inspire me to continue with FSD under subscription. I went into some detail on this in another thread, but to sum up, I found FSD basically unusable in urban driving, at least in the urban area that I live (Ottawa ON) and only moderately good on the freeway. In urban driving, there was a continual need for interventions on my part to avoid accidents, and frequent unilateral disengagement of the FSD. Those aspects of FSD were better on the freeway, but the need for intervention on the freeway and to be prepared for disengagement of FSD still happened more often than I would have liked.
On the freeway, one situation in particular where the Tesla FSD failed to perform was in thinking ahead and adjusting to allow other cars entering the freeway to safely merge. I monitored it closely and FSD was detecting the merging cars well in advance and in many situations would have been able to change lanes to give them room, but it never did so - not even once - in my experience with it. Nor did it use the alternative approach of staying in the same lane but speeding up or slowing down in an anticipatory fashion to make room. In each case, rather, I had to take over controls to do this. In the few situations where I did not intervene, the FSD used very sudden braking to make room at the last second, which was not a good experience and not good driving. I would have thought that managing the freeway merges of other cars is something that FSD would have learned or been programmed to do, and indeed would be an area where FSD could excel. I was quite surprised and disappointed that it was not able to do this. Perhaps Tesla has fixed this problem since then - I was using version 12.3.3. If this aspect of FSD is now fixed, I would be interested to know that this is the case.