My friends and I stayed in Sebastien's flat for two nights.
The Positives: Great location, especially for the price, comfy beds, very clean and no-fuss check-in.
The Negatives: The hallway leading into the room doesn't seem to have great ventilation, so it was always a bit damp and musty. The flat as well had a bit of a musty smell, and we need to open the windows to "freshen" up the place when we came back from a day out. The floors in some spots were always peeling away and uneven – probably from water damage of some sort.