I had the pleasure to stay at German's flat for a weekend getaway in Madrid.
The flat is very central, perfect location to visit the city. The flat is right next to Gran Via and very close to great neighborhood, such as Malasana, Chueca (great location to find good food, places to drink and go out).
German was away this weekend but his brother made the check-in. Everything went smoothly and the communication was perfect.
I would definitely recommend this flat (rather cheap for great location and all the basics needed to have en enjoyable stay in beautiful Madrid).