We stayed at Doerthe's appartment for 3 nights. Communication with Doerthe was very good and as we were getting in to Berlin quite late we were able to pick up the keys from the key safe outside the property.
The appartment was clean and spacious, more than big enough for 4. There was plenty of storage space in the bedrooms and seating in the living area. Doerthe had left us some snacks and water which was appreciated.
The appartment is situated in a lovely area, with lots of restaurants and cafes on the street behind. It is very close to the U-bahn however we chose to walk everywhere, you could walk to Checkpoint Charlie in about 25 minutes. It is very well situated for Schonefeld airport which is about 30mins away by road.
The appartment is exactly as in the photographs, spacious and stylish. The third bedroom is accessed through the second bedroom (not a problem for us as my brother and I didn't mind). The appartment could sleep six adults however this may feel a bit crowded, there were 4 of us and I think this would be about the right amount as there is only one bathroom in the appartment.
Overall, we had a lovely stay and would not hesitate to stay here again if we every visited Berlin again.
Danke Schön!