I can just recommend, the apartment. It is perfect for four Persons. We were 4 boys and stayed for 4 nights. Francesco was a very nice host. As a welcome gift, he puts chocolate and a few bottles of Water on the table. The Apartment was very clean, and you find everything (towels, shampoo, toilet paper etc.) tidy and cleaned up there. He just lives next door, and had a lot of nice tips for us about Berlin. I can just recommend the apartment and will definitely book it again for my next trip to Berlin.