It's a spacious apartment in the center of the city, in the middle of the amazingly lively centro historico. Despite that, the apartment building itself is very safe and quiet. So best of both worlds really!
We liked walking around the neighborhood at all hours, eating breakfast at Gloria's downstairs, biking on Reforma on Sunday etc. There is even a convenience store in the building that we used a lot.
All in all, loved the place. If we come back to Mexico City, will stay here again.