True to its description and photos, Katharina and Peter's place is a great value for money. The location is great (5 mins walk from Westbahnhof station, where the airport bus stops). The building is on a nice and quiet street; the flat has all the amenities and it is well maintained and clean. The communication with both Katharina and Peter was prompt and it was a great pleasure to be their guest. They have a very good list of useful information and recommendations.
Therefore, I would recommend this place without any reservations and if I have a chance I would definitely stay again.