This place was excellent. A great location, a quiet street in a very busy and bustling part of town. At no point did I feel unsafe in this area (though I am white American man, so I can't speak to the experience of others).
The apartment got relatively warm and stuffy during the afternoon and there's no AC, but there is a rotating fan which helps. I imagine that is the case for most places like this in CDMX. Probably best to be out walking, in a cafe or chilling in a park during the hottest parts of the day.
The apartment is in a building with several other apartments that all open on a shared courtyard, which was very lovely and peaceful but be aware that sounds travel pretty well through there, especially because most people have their windows open.
The bed was comfortable and the wifi was fast and strong. I did some work while I was there and I was able to take video calls. I appreciated the fresh flowers, the bottles of water, and the apples that the hosts left for me - that was a great touch!