Many pros, few cons.
We spent 5 days in the apartment, two families, six people; the place is not so big, but, I must say, pretty confy.
The living room is spacious, well equipped and you can have some time toghether there with your friends.
The apartment is newly restorated, tidy and clean; it is also well positioned: very near to the town center, on a quiet street, pretty close to all the main attractions (20 minutes walking distance from the Royal Palace, plaza Mayor, Parque del Retiro, etc.).
The upstairs bedroom is large, with a confortable bathroom, but the windows face a tiny court and some walls (no natural light); the bedroom downstairs is tiny and its bathroom even tinier.. you can barely move inside it. We’ve had a problem right there: on the first day my kid bumped his head on the sink, that slid down with its own mirror. No one was harmed, by luck. We’ve immediatly called our host, asking to fix the problem asap, but he let us down. Since it was the Holy Thursday in the Holy week, there was no chance to have someone who can fix the problem for us; all our efforts were in vain: not really acceptable for a big city like Madrid and for an agency that let apartments to tourists, normally during holidays! We’ve had to stay there four more days with one bathroom in six; consider that the cost we will pay later for the intervention was about 70€, so not a big deal!
Anyway, we’ve managed the situation and have the fun we deserved.
As I’ve stated, many ups, but some downs.. in any case, Madrid is marvellous!