We stayed in Alex's place for a couple of days at the end of a business trip. It's ideal for a few days to visit the city. Best part is the roof terrace, great for breakfast or just sitting out. The apartment is stylish and functional (and interesting as a super energy-efficient structure), with a double bed and sofa-bed in the living area (be aware, if privacy is an issue, that the apartment is basically a large room separated by a folding screen). The apartment is on the roof of a residential building with locked doors at street level, and felt completely safe. Obviously, as a rooftop apartment, there are stairs to climb (no elevator) and the last stretch is a spiral staircase that needs a good head for heights! The area is clean and we had no issues walking to the main areas, at least in daytime (not always recommended in the city, and Uber is very good value) in Mexico City (though the metro can be faster because of traffic).