Overall, I had a wonderful experience staying here. The apartment itself was lovely; furnished to a good standard, comfortable bed, plenty of storage space, nice bathroom (with lots of hot water), whilst the apartment was clean, bright and warm. The local area was filled with nice cafes and shops, whilst it was less than 10 minutes away from a U-Bahn station. Although I didn't get to meet Stefan & Sabine, I had good communication with them and they were very accommodating (regarding an earlier check-in).
I'd strongly recommend this listing to others (and I'd certainly return to stay again). Thanks!