Our family of 6 stayed in Marta's apartment for 5 nights and and it was ideal for our needs. It is very close to the Atocha train station and two metro stops but we walked everywhere. The Retiro Park is a short walk away as are several art galleries. There are supermarkets very close by as well as various eateries.
Marta met us at the apartment and and gave us really helpful information about Madrid. The apartment is very comfortable and had everything we needed. It is also really quiet. Thanks for a great stay in Madrid Marta!