the place is in Cava Alta, in the heart of la Latina, at walking distance to all the sightseeing spots of the center and very convenient with several metro stations.
as the main window is on Cava Baja, a busy street at night, you may expect some noise to come from downstairs.
the living room of the apartment is spacious and the kitchen is fully equipped. the room is essential but fine for a couple (the mattress had its best time already, and feels soft in the middle).
the bathroom would need a little more maintenance, the sink didn't drain properly and overall it seems that water pressure is low (i think it's a common theme in several old buildings in the city).
overall, it's a recommendable place for a couple to stay a couple of days and visit Madrid.