I had the most wonderful 2 month stay at Sofia's apartment and would recommend it to anyone staying in Buenos Aires.
Firstly, the apartment is great. Super comfortable bed with big Smart TV at the end of it. Good bathroom with a great shower. Kitchen is well stocked and has everything you need if you want to cook (which I did almost daily). WiFi is terrific (Sofia actually upgraded it while I was there which I was super appreciative of). Sofa in the living area is really comfortable too :)
The balcony overlooks the leafy street, and I loved just kicking back on the sofa and having the view of the trees right outside. There is a park (Parque Alemania) right outside, and the street below the apartment also has a food market on Fridays which was so handy to get good quality fruit and vegetables.
The Japanese Gardens is a block away and definitely worth a visit. The beauty being that you can go early before the crowds arrive (on busy days the queues are huge!). I went on a Sunday at 10am when it opened and it was so peaceful.
There are so many other green spaces nearby too which are great for jogging, yoga, working out etc.
Oh, and the Planetario Gallileo is also a couple of blocks away. I didn't make it inside, but it is stunning at sunrise or sunset, so worth walking over just to take a look.
Sofia and Paz arranged a cleaner to come in every week I was there, which i really appreciated, and were always on hand to answer my questions. They really are Super-Hosts!!