I'd highly recommend David's apartment. It is very clean, well equipped, with plenty of space and in a great location. We loved the little balcony which looks out over a private courtyard. There are restaurants, shops and supermarkets close to the apartment, and the station is only about 10 mins walk away. It's lovely being so close to Mauerpark too. David is an excellent host, and always responds very quickly to messages. Self check in was no problem - his instructions are clear and easy to follow. If I visit Berlin again, I'd definitely return to David's apartment.