Stayed here for a month and loved the place. Near Chinatown, and a subway or bus ride into Palermo or Microcenter for more social stuff (though Belgrano has plenty too). Bike lane passes in front of the building, so you can bike for hours while staying in that. Big parks nearby.
It is a small studio, but with a well equipped kitchen, giant patio, and two comfortable single beds. Weekly cleaning service was included...an unexpected bonus. Good WiFi, hot water, cable TV, and a bunch of books.
Though Olga lives out of country, it is easy to communicate both with her and her local property manager. I would certainly return.