We stayed 3 nights in the Citizen Hotel. The room was as expected very small, but fine for sleeping. The location was about 30 minutes away from the city center with one tram.
However, there were some dusty spots in the room and a weird smell (we don't know where the smell came from, maybe the sink?). Also, the rooms weren't very soundproof. We heard the people from the other rooms as well as outdoor noise.
For one night, the hotel is probably fine, but i wouldn't stay longer.