Baharbin is a cool person, he gave us a couple of good tips about where to eat and visit in Berlin. I think however that his place could be a bit nicer, perhaps he is not aware that the cleaner does not do a good job. The house was very dusty. We were four friends that three of us were supposed to share Baharbin's house and one had a room in a hotel. Since the place was very dusty, I had an allergic reaction and had to move to my friend's room in hotel.
There was a problem with wifi as well. Baharbin tried to solve the problem, but the connection was still slow. It only had a reasonable speed after midnight. I would recommend to guests to download offline google maps before arrival to Berlin.
All in all, we enjoyed Berlin. It's a cultural and wonderful city.