The apartment has a great location and is in walking distance to almost everywhere. Supermarkt is close and the Apartment has the very basics you need.
It is a little bit noisy as you can hear the nabours come and go and due to its central location the street is very busy and you hear the busses going by.
All in all, could be a little cleaner, but for a long weekend, with the goal to get to know the city of Madrid by foot it was nice.
Contact to Sergio was also good - quick and friendly.