Just too noisy during the night.
The apartment was fine. Nicely furnished, very clean, well located. Everything was perfect. Except the noise during the night. The apartment is located on the first floor, with the main bedroom facing the street. This is a neighbourhood with a lot of bars and restaurants, and the street is full of young party goers and drunk people during the night, screaming, shouting, calling for the police, laughing, crying, ... In the apartment, you can hear every word they say. It was really difficult to find some sleep. Usually, I am not sensitive to noise during the night, but this kept me and my wife thoroughly awake for the 5 nights we spent there.