Andres's place is a nice, cozy spot to spend a few days or even longer. It's in a neighborhood within downtown which feels pretty safe and is usually quiet. It was a bit difficult for Ubers/cabs etc. to find, as the apartment is one block down a small street which the online maps don't always locate properly; however, once we found it the first time it was easy to return to.
I stayed with two friends and we felt comfortable during our stay. The apartment isn't large, but in the middle of a city like Ciudad de México it's probably rare to find big spaces for this price. Andres was extremely easy to talk to and quick to respond to my questions and needs. The process of checking in and out was easy and stress-free -- just a couple of lockboxes to open the gate and door, which left us feeling doubly safe.
It's worth noting that there is only a stovetop cooker -- not an oven -- and that the stairs up to the 3rd-floor apartment are a narrow spiral. It's nothing too hard for the average person to handle, but it could be a bit tricky if your luggage is heavy or large.
All in all, I would definitely recommend Andres' place for anyone willing to climb some stairs and who would like to be close to everything -- downtown, the airport, etc. -- without spending extra to be right in the heart of it. Many thanks to Andres!