The apartment itself is a very nice space, not huge but big enough for a base from which to explore Madrid from. We stayed here with a toddler and we all enjoyed our stay greatly. The biggest selling point of this apartment is the location. The street is a great little street, with a nice sound of bar/cafes below without being too loud. It really makes you feel like you're hanging out with the locals even if you're just listening from above with the balcony doors open. The area the apartment is in is fantastic – lots of independent shops, bars, cafes, spaces, the CaixaForum at the end of the street (which is a fantastic cultural space), the three big art galleries within short walks, Retiro park only 10 mins walk away, and two Metro stops within short walks.