CB was very responsive - within minutes always. The location is superb - minutes away from lots of restaurants and walking distance to many of the big sights in Madrid - the Prado etc.
We followed CBs recommendations for restaurants, groceries etc. That put us in some excellent local places and generally avoiding touristy restaurants.
We were two couples and there was plenty of space - lots of light pouring into the apartment even in this compact area of Madrid
We drove and left our car in a parking garage for the full four days we were there - I would take a train the next time as the car was not useful at all.
I would highly recommend CB s a host