Fernando's apartment is fantastic. I would stay again! Honestly. My group was a group of 5 and we were traveling for a family wedding. We are pretty mellow and a mix of Chicago city and suburb people.
Service: fantastic! All emails were answered within 24hours and I was contacted by Rosa (the person letting me in the apartment) 24 hours in advance to settle details. Rosa was very patient and friendly while I stumbled through my grammar and made sure I knew every detail.
Details: I loved the modern art, cool furniture and everything was clean! Note. I live in a major city and Madrid's bedtime is probably around midnight. (Children are up walking the streets with their family at 10pm.) So I did not even notice street noise and you are on a side street with shops and food places that close about 11pm, so I don't know what other reviews were complaining about. Also details I questioned: there are a total of 4 levels of stairs. Also there is a washer but you have to line dry. (Drying is surprisingly quick with Madrid's climate). As for AC, I stayed in Aug, it was about 97f(37c) degrees when I stayed and I thought the AC was great for a window unit but the back room does not really get the front room's air. I did not mind because you can close off the back room and I kept the windows open in (which looks over a quiet private court yard) and used the fan. I thought it was great and felt like about 73f(23c). (Also Madrid gets cooler at night.)
Location: Very Central! This is where you want to be if you want to see Madrid! This apartment is right off a popular train stop (maybe 2blocks) and about 1 mile-ish from most of the popular tourist museums. A 5 minute walk from a couple churro spots. Also you can't help but stumble onto cute shops and restaurants in every direction. Easy to get to from Atocha train and the Airport! (It is so walkable I did not really use the train except when I was dragging my luggage.) Also none of the people in our group felt unsafe walking to the apartment from the train or where the cab dropped off.