I went on one with a bed (6 people) some years ago from Berlin to Vienna and it was a nightmare (OEBB Nightjet). It stopped several times and there were constantly people getting in and out of bed, storing suitcases, getting dressed etc.
The 6 is too much for me.
As for the stops you get used to it, I couldn't sleep during my first night train trip, after 5+ I know sleep like a baby. I haven't used planes in a few years too, and for my use case it's actually cheaper/more convenient than planes