We have stayed at several private apartment AirBnBs as well as some that are not actually someone's home (like this one.) While our experience at other "non-residence" stays was not so good, Katharina's place is well-appointed and quite comfortable and was the best so far.

The location next to the Westbahnhof is very convenient for getting in to the city, shopping, etc, but was still very quiet. Communication was easy and they met us at the apartment for a smooth check in.

Thanks Katharina and Peter!