The washing can be placed in the machine, in the morning, and you can then come home to nice clean dry clothing. The main decision when looking to buy a machine is whether you are able to connect it to an outside vent or not. A vented machine requires the ventilation pipe to be connected to the outside world via an external wall or window. A ventless appliance passes the warm air through a condenser which removes the moisture. The water produced collects in a tray which will need to be emptied regularly.
Overall these machines are great for small spaces and are worth looking at.