We stayed in Sigrid's apartment in October 2013 and can definitely recommend it. Sigrid and Fabian were both a pleasure to deal with and everything was as described. Sigrid's recommendations for restaurants etc in the area were spot on also and we really had a great trip. It's located just a short walk from the U8 at Moritzplatz and it's particularly great for anyone who wants to check out Kreuzberg as although it's just around the corner from Oranienstraße it's a quiet and safe retreat when you need to relax.