Both times I'd say well rested would be a stretch. The first time felt a bit like a magic carpet in that I got somewhere while using up no useful hours but it still wasn't perfect.
I suppose it’s the novelty of sleeping in a moving vehicle, my flight attendant friend said it took them a while to start sleeping well on long haul flights.
Perhaps with a lot of benzodiazepines or drowsy anti-histamines I could attempt to sleep well in a sleeper train, but not normally. Happy for those who can of course.
Do you think it's the noise for you, the movement, or something else (like lack of privacy)? I started taking earplugs with me for any kind of trip now, they are a godsend.
Most sleepers also offer cabins with proper beds (for a premium).
But then again some sleepers (Shiki-Shima in Japan) are like being in a luxury hotel. Rather enjoyed having a soak in the tub in my suite.
So as an individual traveling alone, you know your limits and can pretty much figure out if that way of travelling works for you. For a family, you are pretty sure at least one member of the family will have a rough night and complain in the morning.
A sure way to spend good night while travelling is to be very active during the day. You sleep much better if you have walked for 15 to 20km around a city to visit it than if you have been idle most of the time and taken taxis and buses whenever you could. Most lazy people don't understand that rest has to be earned.
And, yes, especially when time zones are involved, sticking to a schedule and getting exercise helps.
The definitely ran between Germany and the Netherlands in the 00s because I took at least one trip that way.
* couchette (6 couchettes per cabin, less comfort)
* 2nd class bed (3 beds per cabin)
* 1st class bed (same as 2nd class, but 2 beds per cabin)
* 1st class private bed (same as above, but without roommate)