We took the flixbus from Boston to NYC and back in May 2022, as we were advised by some friends to avoid flying for such a short distance (I tried to book Amtrak and my payment never worked, no matter whether I used the website or app). It was okay on the first trip but the second trip was massively delayed by traffic and there wasn’t any toilet paper in the loo. They seem to generally provide a reasonable service and I can see who might have a use for it, but I would personally never use them again!