Axel and his flatmate, Katharina, are really nice and welcoming. We had great talks with Katharina and she gave great advice for pour stay in Berlin. The flat is very well equiped and the rooms look nice with high ceilings and good dimensions. The flat is not far from the center if you take the tramway (lign M4 or M13, 15-20 min from Alexanderplatz). You can easily buy your food nearby or go to restaurants. I warmly recommand the appartment and most of all its owners. We had a great time!