Nader was a great host and replied to inquiries very quickly, even during our stay. The location is perfect, only a few steps from Gran vía and Metro. Most tourist attractions are at a walking distance.
The apartment could use a few touch ups, but it's clean. Even though it's very close to all the hustle and bustle of Gran Vía it's really quite inside, you don't hear all the traffic. The only thing you could hear was some music (not very loud) from a concert room next door to the building, the upstairs neighbours and some construction going on below the apartment. It didn't bother us though.