Andreas' place is in a quiet, residential neighbourhood but a short walk from the U-Bahn (Osloer Strasse), which also has a direct bus to Berlin Tegel Airport; there are local amenities (large supermarket, bars and bistros) close at hand too.
The apartment is very clean, has two good-sized rooms - a nice-sized bedroom and another bed in the living area, is well decorated and furnished, with a small balcony and all the essentials one could require for a comfortable stay, with a fully-equipped kitchen, large fridge, washing machine, iron, hair dryer etc.
Andreas is the most marvellous host you could imagine; he insisted on collecting us from the U-Bahn and gave us a complimentary bottle of wine, then took time to explain all that Berlin, Potsdam & Oranienburg had to offer, with many handy hints and suggestions. Before we travelled, Andreas was extremely prompt in responding to messages and also gave detailed instructions on the quickest and easiest way to travel to the apartment from the airport (in our case, Schoenefeld).
I would also like to mention Herr Schroeder, who lives two floors down in the same block and who was available throughout our stay in case we had any problems and queries; both Andreas & Herr Schroeder are very kind people whom it is a pleasure to have met.
At the end of our stay, our return flight to the UK was cancelled and we had to stay in Berlin for two additional nights; although there were new guests arriving at the apartment, Andreas (as we had asked if we could extend our stay) went "the extra mile" in trying to find us alternative accommodation, even though it was nothing more than a favour to us. You could not want for a better host.