Vivian's location is perfect! The grocery store, a huge shopping malll and the metro are all within a few blocks. It's a few blocks from one of the main streets in Buenos Aires and you can find everything there (Corrientes).

There are four bedrooms upstairs and two bedrooms downstairs. It almost feels like a dorm setting because there are young college-aged people (mostly Brazilians when I was there) coming and going.
The heater in the room was a life-saver. It gets cold in Buenos Aires and the heater made the room feel nice and cozy.
Vivian makes you feel at home and she enjoys interacting with her tenants. She is a musician and knows about many events in the city.
(A minor note - the bedrooms downstairs are right in front of the dining area. The bedroom door is a bit thin and so you can hear the conversations taking place right outside.)