We spent 6 nights at the apartment of Nicholas Gilman. He and his partner Jim Jonhston graciously received us at 9 pm. They are both artists and have written books about Mexico City; a copy is available at the apartment.
The apartment has all normal facilities (including a full bath), it is nicely decorated (see the pictures on the website) and has many pictures, books about art and cooking and finally a collection of CD's to listen to. In short, a home-away-from-home.
The Condesa area where the apartment is located is a truly enjoyable area, with many shops, cafes and restaurants. As Europeans we enjoyed walking around this historic Art Deco area. To us it also seemed very safe as it is an area where people live. The Parque Mexico is just around the corner. The Condesa area is also central for sightseeing with most sights a short and cheap taxi ride away or with public transportation (which we did not use).
The apartment is highly recommended.