We had a wonderful stay here in Buenos Aires for our honeymoon. Flor and Demian were extremely gracious hosts, giving us extensive suggestions on things to see and eat in the city, and even making us reservations at restaurants since our Spanish isn't the greatest. They also helped arrange cabs for us to and from the airport. At the same time they gave us our space to explore the city on our own. Exactly what we want from a host.
The apartment itself is cute and cozy, with a small kitchen that is helpful when you're sick of eating out for every meal. And it really is truly central to everything--it's in a very safe neighborhood and is walking distance or a short cab ride away from Recoleta and Palermo. It is also very close to a grocery store, a cool little park/playground, and some good, inexpensive restaurants as well.
The next time we're in Buenos Aires, we hope we can find a place as good as this again.