Book if you want central Madrid. This place is only 15 minutes walk from Puerta del Sol.
DO NOT BOOK if you want clean, damp and odour free accommodation or if you want to be able to cook, or if you want a responsive host who even attempts to solve the problems 24 hours in to a 72 hour stay and/or offer a part refund.
I booked this 15 December for a NYE weekend in Madrid (30/12-02/01). At no point did the host tell me in advance, that there was a severe DAMP PROBLEM. Neither did she tell me the only cooking utensils were a wooden spoon and soup ladle. The radiator supplied for heating was inadequate also.
When I alerted her to all of this (day 2), her response was to say the damp was out of her hands, turn on the AC unit to 'heat mode' and that she was aware I couldn't even fry an egg!
When I requested a part refund, this was ignored by the host. Airbnb part resolved my issues.