We messaged Maria Laura before arriving and met Sergio. They were very prompt in responding -- friendly and wonderful to chat with. The apartment is very clean and the amenities are as promised. The location is perfect -- close to the cemetery, a major subway stop, and a corner's turn from a mall with an ATM and currency exchange.
One incidence I feel I should mention is that the electricity went out twice during our stay, resulting in no light, A/C, or hot water. This is unusual and certainly not the host's fault. There seems to be construction in the front, which may have contributed. Please be mentally prepared in case you visit.
Sergio also let my friends and I leave our suitcases until 6:30pm on leaving day! We are very grateful because otherwise we would have had to lug them around all day.
The other thing is -- when they say no essentials are included, it means no ingredients (salt, oil, sugar, anything) in the kitchen. Please be prepared to buy them. Also, one roll of toilet paper is included, so stock up if you stay for a few days! This is all noted in the description, but I would like to let other travelers know.