This place possibly offers the best price / quality ratio I had ever experienced in Airbnb. The location is superb (just 50 meters from tube station) and the beauties of Plaza Mayor, Puerta del Sol, etc.
It is small but cozy, brand new, perfectly clean, absolutely silent. Perfect for a couple wanting to spend few days in Madrid and enjoy it fully.
And Carmen guarantees a very fast response on any request. Very strongly advised!