I had a wonderful experience staying at Carlos's place. Carlos and Susana are laid-back and very helpful hosts. Carlos replied immediately to all my messages before I arrived. When I got to his house, we sat down and got to know each other a bit, and Carlos guided me through a tasting session of mezcal and other liquors from Oaxaca - an AWESOME welcome.
My room was simple, private, and clean. It has a great little balcony overlooking a quiet street. Carlos rents out several rooms on airbnb, so there was opportunity to run into and speak with fellow travelers in the common areas. This setup also took away the usual awkwardness (for some of us, at least) of traveling alone and staying with strangers... Despite the extra people, the house was always serene. I was travelling to work on a creative project, and was able to get a lot done during the first half of each day before striking out to see the city in the mid-afternoon. Also: I was thrilled to have access to Carlos's kitchen, which I used two or three times a day to cook my own meals.
The neighborhood is more relaxed and far less touristy than the city center, but all your necessities are within 5 or 6 blocks: small grocery and convenience stores, a Banamex bank, along with plenty of small restaurants, a few bars, and, of course, street food vendors. It's also about a 7-minute walk to the Eugenia metro station, which took me wherever I wanted to go pretty quickly and easily.
Next time I travel to Mexico City, I'll be hoping Carlos's place is available.