This was my first time in AirB&B and I enjoyed a lot my stay at Nicolaj´s place.
The room is very comfortable and with a lot of small details very well appreciated by the traveler (international socket adaptors, USB chargers, tea & coffe, a little mini bar).
Very welcoming house but also respecting your own privacy if you want so. I would definitely recommend to stay at Nicolaj´s If you want to visit Copenhagen !