On our Eurail Pass, we added the extra for a sleeper berth for the 12 hour trip from Budapest to Berlin. The train began as a very very long train on the Budapest platform, with some carriages going to Prague, and others going to Warsaw and our going to Berlin. I monitored our trip using the Navionics navigation software on the phone that we use as a backup on board SeeBeeZee, and noted that for most of the night, the train was sitting on 160km/hr. The conductor had initially told us that we would have the compartment to ourselves, but at the last minute, another couple that bought their ticket on the platform were brought in, and had to fold up the beds that can be seen on both sides of the compartment. Even so, the rocking motion of the train gave us a good sleep at a much cheaper rate than a room in a BnB in Berlin.