The walls are so thin you can clearly hear every conversation in the flat (and I am a heavy sleeper who usually doesn't mind). There are 4 rooms with random travelers and there is no supervision from the owners. So when at 1am some girls decided it would be a good idea to sing Asian pop songs... well, you get the picture. Furthermore, the doors make very loud noises when you open and close them... you keep waking up all the time. I do not recommend this flat for anyone who needs to work/sleep/do anything serious. This is a nice place for young tourists and students I imagine.
On the plus side, things were as clean as they get. The flat and building are old, but the owners did their best. The sound issue is really unfortunate, but I feel I need to be honest here.