I went to Berlin to do a research internship for three months (September, October and November 2022). I stayed at Brigit and Hassan's place during that time.
My general opinion of the accommodation is pretty good. The house is very nice and Birgit and Hassan are welcoming and friendly. The room is very comfortable and well equipped, as well as the kitchen. Birgit recommended many places in the city that I liked very much.
As things to know, the windows in the kitchen and the bathroom are always open so that there is no smell in the kitchen and no damp in the bathroom. You get used to it, but if you get cold easily and you go in winter, it can be a problem.
Also, the terrace can only be accessed through Birgit and Hasan's room.
Finally, it is common for Birgit to go into the room to ventilate, adjust the thermostat, take clothes to do the laundry, etc. In my case this was not a problem, but I think it should be discussed if it was a problem for someone else.