About the Night Jet!
Ok, I think I will not be traveling in a night train without a bed again. It can be done, and it is cheaper. I survived. But at least for me it's not very pleasant.
I assume much of it has to do with the shape of your body. I'm thin and kind of tall, and that's the worst shape to sleep in hard chairs! Even if you have 3 of them to yourself ahah I slept for around 5.30h and rested laying down for about 2h more.