What a great stay we had!
Carlos's apartment is really the best place to stay if you want to stay in Madrid for a short citytrip or even a longer stay. It's such a cosy place at a perfect location! The apartment is at walking distance of the main city center attractions and near many metro stations.
Carlos is such a wonderful guy. Unfortunately we didn't meet in person (we arrived in Madrid very early), but he arranged everything for us so we could drop off our bags at the apartment when the cleaning lady was there and she gave us also the keys. Carlos provided us plenty of information about Madrid, the coolest hotspots, great eating and drinking places, tips and tricks, ... Also the communication with Carlos went very smooth!
If I would return to Madrid (which I defenately will), I would certainly like to stay at his place again!