We stayed 7 days in Karin's apartment as a party of 2 for tourism in Madrid. We had a great stay, better than what we expected from the photos and description on AirBnB.
The location is really great: very close to Chueca underground station, within walking distance (less than 30mn) from all major tourist attractions. The supermarket in the nearby San Anton market provided everything we needed for food with good quality, and there were smaller food shops in the area as well.
The flat lies on the second floor, there is a lift but you still have to walk up or down half floors to reach it. It has a large surface. The lounge looks on to the street, which was reasonably noisy, but the 2 bedrooms look on to a small courtyard, which makes them less bright but also very calm. The apartment has been entirely renovated and we did not have any issue, everything functioned well. We took most of our meals at home in the evening and the apartment provided everything we needed for this. A part of the furniture is of the ubiquitous Ikea style, but Karin has also used some older pieces of furniture or decoration which provide the apartment with a more personal touch and contribute to its comfort. We found the bed particularly comfortable. The apartment was fitted with everything we could need (towels, toiler paper, soap, shampoo, etc.).
Communication with Karin was fluid, efficient and friendly. Check-in and check-out were very easy. We would definitely come back for an next stay !