Jonathan's condo is very well located in the Belgrano neighborhood. At walking distance you have many cafes, bars and restaurants, as well as a myriad of public transportation options. It's also very close to neighborhood supermarkets and kiosks.
The condo was very clean, and in a safe neighborhood. Jonathan and Laura (his assistant) were always readily available and checked in periodically via text message to make sure all of my needs were covered, and if I needed any help.
There's a garage right next to the building where the condo is located with very good pricing for long term (14 day) parking. I highly recommend working with them if you have a car, especially since parking (anywhere in Buenos Aires, in effect) can be very challenging.
I would definitely stay at Jonathan's condo again in the future, and recommend it!