Brian was the perfect host! He and Ariela actually saved our trip by finding my girlfriend's passport that she thought she'd left in the cab we took to the apartment.
Speaking of the apartment, the location is the best we could hope for, providing the comfort and convenience we needed (the AC is a must during the BsAs summer). Is also located at a historic little street, the Pasaje Carlos Gardel, that has plenty of options for eating, the mall and the market are right across the street and the subway - our mean of transport of choice - was a 5min walk from the apt (station Carlos Gardel).
I definitely recommend Brian's Tango Suites for everyone planning to go to Buenos Aires and not just for everything I said earlier, but also because of the little things too. Brian was always very willing to help us, even when we were still in Brazil, replying to all my texts right away; he also lent to us a Sube card that allowed us to move through the city by bus/subway; he left us two SIM Cards so we could use our phones there (in most places we looked, you need an Argentinian ID to buy a SIM card); and plenty of other stuff that made our trip even more special.
I thank Brian again and hope to go back to Buenos Aires very soon and, hopefully, stay at Tango Suites again.