We stayed two weeks at Agostinas apartment, which is very nicely furnished and fully equipped. It is close to the local Subte (5-10 min walk), supermarkets, grocery stores and most important of all: restaurants.
Ileana, Agostinas mother, was very helpful and always contactable for questions. We only had contact with Agostina via AirBNB, but she was very friendly in her messages, honest about ongoing work on a nearby construction site and she responded quickly to our questions.
We enjoyed our stay at the apartment, but If you are a light sleeper, maybe you should bring earplugs. Buenos Aires is a busy city, with lots of traffic and especially Palermo has an active nightlife :).