The apartment was outstanding and the location was perfect. Shortish walk to the social center of the city. Very close to the golden triangle of museums (Reina Sofia, Thyessen, El Prada) and train station. Building is connected to one of the national theaters. Major grocery store, cab stand and metro station one block away. Well appointed kitchen. Had everything we needed. Strong internet.
Cons: apartment next door was being renovated and construction (loud) started promptly at 9 am even on Sunday. Internet went out for a period when the temperature outside went below zero (c). Running all the heaters to warm up the apartment when we arrived apparently blew out the power. But the hosts were very responsive in helping us get it back on even though it was after business hours.