I really enjoyed my stay! The flat was clean, very quiet, and was located in a really cute neighbourhood with access to all sorts of incredible restaurants and shops. The U and S bahn are about a minute from the flat making it really easy to get just about anywhere in Berlin, including to and from the airport.
Frank provided detailed and clear instructions on how to get there via transit and how to get in, making the final leg of my 24 hour journey the smoothest part.
I would definitely recommend.