We spent a month at Susana‘s place.
The apartment itself is really cute and cozy. Susana was a great host; she was always there for us when we needed something and took good care of us. The internet connection is very fast (we measured upwards of 30Mbps) and, although the router is located upstairs, the WiFi was good within the entire apartment. The bed rooms are oriented towards a court yard, shielding them from most street noises. The mattresses were decent, and the shower provided plenty of hot water. We had all the blankets, pillows, and comfortable chairs we needed.
That being said, we personally didn’t like living in Xochimilco very much. The immediate neighborhood felt quite dirty and uninviting. There seem to be no nice places to sit outside and enjoy, such as cafes or parks. It's all loud and crowded, with lots of traffic. There is a limited selection of corner stores and small supermarkets, but if you need anything more specialized, such as natural yogurt or fresh coffee, you’re out of luck. Although Xochimilco is connected by light rail, it's still pretty far from the more interesting parts of the city. Be prepared to spend hours on travel time if you plan to leave the area.
What bothered us the most was the local custom of blowing up extremely loud fireworks on a daily basis. Apparently, this is done as part of religiously-motivated festivities that occur year-round. Many locals are annoyed by this, but are used to it. However, for us it was unnerving and really made us want to leave after a while.
All in all, if you’re looking for a cozy place to stay inside and work online, Susana’s apartment is a good choice. If you’re fine with cooking at home and don’t need any “fancy” stuff in the neighborhood, you can purchase produce at the nearby market. Just be sure to be aware of the limitations of Xochimilco if you’re going to stay long term.