We met Miguel and his wife briefly but they were ever so helpful, friendly and flexible to our requirements. We had night flights and she waited for us in the apartment on our arrival. They even lent us a travel cot and lots of different blankets and a cute baby towel for our baby daughter. The apartment is very big, tidy and equipped and it is near a metro station and within walking distance from Plaza Mayor (even with a pushchair!) It is located in a very quiet zone and there is a small park just around the corner with a kids play area. There are lots of books in the apartment and a big TV.
We definitely recommend this apartment and we would love to stay there again if we go back to Madrid.