Staying with Joseph was really nice! He and his wife greeted us in person when we arrived, even gave us some holiday cookies.
One quick warning is that there is construction going on nearby, so you can definitely hear that in the mornings. It woke my partner up most mornings, but I was able to sleep in some days.
The flat itself was very big, all the furnishings you'd need for a basic stay. I did notice that the floors were very cold and a bit dusty/dirty being stone, especially since we were there in the winter, but we did our best with the little radiators in the flat and blankets.
Overall though, the flat is very well equipped for any size group, and would be especially great in the summer!