Great place to stay in! We were group of freinds (7 people), visiting Madrid for 5 days. Apartmant was big enough for all of us to fit in, beds are big enough for two persons, only kitchen is a bit small, but that wasn't a problem for us, because we mostly ate outside. Location is fantastic, you basicly can walk to every important sights in centre, supermarket is around the corner, also some good restaurants.
Mar was very helpfull, she gave us a map of all things to see in Madrid, also some advices where to eat, what to do. She is very responsive, so if you need anything, she will respond to you quickly.

It was great experience, if we return to Madrid, we will contact Mar for sure, to book this apartmant again!