I've spent a month at Maria's place during my Erasmus exchange and I can confidently say that it was by far the best experience out of the places I have stayed in Madrid, considering both the price/quality ratio and the host herself. The apartment is really big with a decent sized, clean kitchen. It never gets too crowded, as Maria rents only 2 out of 6 rooms in the apartment.And Maria herself is very friendly and helpful. You can communicate with her in English without any problems. Overall, I reccomend it a lot.