In the sleeping cabins I can sleep fine, but they're usually really expensive. In the couchettes I can sleep about 50-60% of the time. In the seats, not at all.

In the sleeping cabins I can sleep fine, but they're usually really expensive. In the couchettes I can sleep about 50-60% of the time. In the seats, not at all. So I go for couchettes. One time in Sweden I found that the sleepers were only 10 euro more than the couchettes, so then I took one.