Sonja is an excellent host and she seems to have thought of everything. Some drinks and snacks are waiting for you upon arrival, much welcomed after a (tiring) journey. She is friendly and helpful if you have questions about the apartment or how to find your way in Berlin.
The description and photos of the apartment are accurate. The neighbourhood was quiet but the metro takes you down town in no time. Also bikes can be rented close by.
We (2 persons) stayed with Sonja for 3 nights and we can definitely recommend this place for your stay in Berlin!