Carmen is a very nice host! Although she doesn't speak English that well (while I only knew a few words of Spanish) we had several very interesting and pleasant chats.
The room is very beautiful and clean. The bed is just perfect. The apartment is cosy and has all the luxury you need.
Carmens apartment is very close to metro station 'Barrio del Pilar', which brings you to the center of Madrid within 30 minutes.
I would definitely book the room of Carmen again when I visit Madrid.