Sleeper trains in Russia cover huge distances, and the roomettes are designed to convert for day use. It is still how people choose to travel for journeys up to 1,500 miles. I travelled 1st Class Murmansk - Moscow, which took two nights and one day, costing about $130 including food. The roomette was shared with one other, but was unoccupied for the first 24 hours. The trains are not fast but were always punctual. There is usually somewhere to leave your bags on arrival, or a hotel at or near the station, which will store your bags during the day. As city-to-city travel, it compared favourably with spending most of a day at airports/flying/in taxis - and having to pay for 2 more hotel nights.