We enjoyed almost everything about our stay in this small, well appointed studio apartment. It's very close to the Gran Via and Sol Metro stops, and the direct airport bus stops at Palace Cibeles just a 10 minute walk down Gran Via. It overlooks a commercial passage way that is gated at night so it's fairly quiet.
Have a washing machine/dryer combo unit in the apartment was very convenient, though no instructions to the machine were provided. We found guidance on the manufacturer's website, which proved most helpful.
The primary issue of concern with this unit is the lock to the building's front door doesn't work properly, so getting into the building requires a lot of fiddling with the lock to get it to open. This took several minutes each time we returned to the apartment and became quite frustrating. The apartment owner's advice was to "jiggle it". I don't understand why this know issue has not been addressed.