Penelope's place feels very safe and calm. However, it is aptly located in a very central and lively neighborhood. There are lots of restaurants, bars and other shops around - from small local cafes and book stores to high end, fine dinning, restaurants. It is walking distance from two parks (one of which is the very central, and museum packed park of the Bosque de Chapultepec and the other is the small but lively park of Parque México) and about an hour walk from the historical district - with many nice attractions to see along the way.
The apartment we got was convenient and unique and Penelope equipped it with a lot of maps and helpful information regarding the surrounding area.
The complex is very cool with a Hostel vibe and a nice patio on the top floor with a nice view.