I can't recommend this apartment enough.
Fantastic location. Close to metro links, lots of wine bars, restaurants, cafés and bakeries within a minutes walk. Main sites around Berlin just a few stop away on the metro.
Gerhard was an amazing host with lots of tips for places to see and things to do in Berlin.
We had a fantastic meal at Wirtshaus Heuberger restaurant and Honigbiere had a delicious breakfast, both just around the corner from the apartment.