Apartment: The apartment was very nice and exactly as described. It had everything needed from hair dryer to ironing machine. It also had a washer that was very helpful. The shower was nice and the bathroom plentiful. It had coffee and alot of things to make us feel at home. A couple of things to improve, the bed is a little small for 2 people, but I did fine.
Location: The location is great, it's very close to everything. Halfway between El Sol and Gran Via. A lot of restaurants and nightlife around. If you know Madrid, you know that the street it is on it's kind of a red light district, but definitely not dangerous, a lot of working girls around the building, but they don't bother anyone. Like someone mentioned, there seems to be a "girls" house across from the apartment, but again no noise from it or anything like it.
The double windows are definitely a nice touch and helped with the noise, but I was there with a toddler and on a weekend so there was a lot of noise still not a big problem if you like going out late.