We stayed in the flat with 13 people for one weekend, which is definitely possible. The flat is like shown on the pictures. It’s located very central and everything was very clean and tidy. Unfortunately one sleeping room of 4 rooms and the living room/ kitchen has no windows at all and there is no aircon.
Another thing was the shower, there is absolutely no water pressure, therefore it took ages until everybody was finished with showering.
All in all it was a nice flat, for a good price. But the showers (water pressure) and the missing Windows were two bad points. Accept of that we had a good stay :)