We stayed at Gaston and Barbara's for just under 3 months when we were in Buenos Aires learning Spanish. I would 100% choose to stay there again if I was coming back to the city. The apartment is great - big, light and airy rooms, fully equipped kitchen, great shower and the bed is so comfortable (these are the things that make somewhere a home from home in my opinion!). On hot days, the pool area is great to sunbathe and swim. There is super friendly 24hr security which makes you feel really safe - even though the area is one of the best in Buenos Aires. The apartment is perfectly situated in Palermo Soho - there are bars, cafes, shops and restaurants on your doorstep. But you are also a short walk from Palermo Hollywood which is another great area to go out in, and you are a 5 minute walk from Avenida Santa Fe, which is a transport hub with buses going to all areas of the city & also the Subte (metro) if you prefer.
Gaston and Barbara themselves are absolutely fantastic hosts - totally deserving of their 'super host' status! Throughout our stay they were so helpful whenever we needed anything at all. Everything was done so quickly and they really went out of their way to make sure we had a good experience. They're both just very nice people to chat to as well, and often gave us tips both for the city but also for our trip post Buenos Aires - they even lent us their GPS to take to Bariloche.
Gracias Gaston, Barbara (y Olivia!). Nos vemos cuando volvemos en el futuro!