About 20 years ago, I visited most of Europe’s major cities over the course of a two-month trip, traveling primarily by night train. Each overnight ride saved me the cost of a hostel or guesthouse, and I’d arrive in a new city each morning feeling refreshed because of the train’s sleeping accommodations. There used to be a similar service between Toronto and Montreal (both directions), where the train would pause for…
"I’d arrive in a new city each morning feeling refreshed because of the train’s sleeping accommodations." Aeh, where were you travelling? Many countries did not have sleeper trains. Don't get me wrong. I did the same, travelling at night in trains, and it saved me a night in a hotel. But I did not arrive well rested, I arrived train wrecked.
Actually Spain seems to have more to offer according to this map http://www.night-trains.com/europe/
edit: Nope, Spain is pretty almost void of night trains https://en.wikipedia.org/wiki/Trenhotel