Gerardo's apartment is fantastic! It's located in the heart of Roma, on a quiet street just off the large avenue. There are literally dozens of restaurants, cafés, bars, and so forth within walking distance. I stayed for a month and enjoyed every bit of it—you can walk from here to essentially everywhere you'd like to go (the historical center, Condesa, Polanco, Chapultapec) or easily catch the metro or a bus. The neighborhood itself is very enjoyable and safe to walk around in.
The apartment is spacious enough and the WiFi is decent to get work done from (e.g. to take video calls). I did not have any issues with the apartment and definitely recommend staying here if you're in Mexico City!