This place is great. I spent a month there, and I strongly recommend it to anyone who travels to Mexico City.
Here are some of the reasons:
1. Carmen and her son, Sebastian, are wonderful hosts. They have been thoughtful and responsive. They went above and beyond to make my stay enjoyable. They helped me learn about the neighborhood and local culture, showed all the places that I might need (bank, atm, groceries, cell phone company, nice places where to eat out etc.). My trip to Mexico City was work-related, and many times during the month I spent there I relied on their support and kindness when I encountered some unforeseen circumstances. I am incredibly grateful to them for making my stay so great.
2. The area, La Condesa, is one of the best and the safest in Mexico City. It is very walkable: has a lot of restaurants, bars, coffee shops, bookstores etc.
3. The apartment is very nice. Your room will be spacious, clean and comfortable. A cleaning lady visits twice a week to clean the room. The living room (which is shared with the members of the family and occasional guests) is also spacious and comfortable.
In sum, if you need a place to stay in Mexico City, look no further!