Not our first trip to Bs As, have always stayed in private apartments. This one appealed to me as it was from the time of Argentina's economic peak, old and huge. The space did not disappoint. 4 or 5 meter ceilings throughout, doors that approach 3 meters high, a beautiful old space with the right patina. Unusual layout which has been optimized as best it can to modern expectations, the kitchen and 2nd bath and 3rd bedroom/bath loft are across the private courtyard from the rest of the apartment, in use not a problem. Appreciated the heavy much-better-than-typical pots & pans, by the way.
Guests should pay close attention to the location of the circuit breaker boxes (about which the host goes into in detail), you will likely trip them. For instance, the main bathroom circuit includes the electric water heater, so a hair dryer may well overtax that circuit after a shower. No big deal, just flip the (modern) breaker and you're back in business. There are 5 AC units here, no reason to ever have more than 3 on at a time and we were perfectly comfortable keeping them at 24 C or higher as recommended and we diligently turned them off when we went out. WiFi works fine. Cable TV has lots of US programs many of which are in English on SAP.
Cautions? Well, there is an ongoing issue with power in Buenos Aires, and when it goes out, so does the pump which supplies the rooftop water pressure tank (like every other BA building over 1 story). The rub here is that when the power comes back on the pump may not, needing to be reset, and availability of someone to reset it (it's locked off the lobby) is limited. The hosts are not authorized to access the pump room, for instance. We were blessed with fantastic weather for mid-summer, and the pump only shut off once, and someone was available in the building to turn it back on. Had it been a hot week this could have made the place essentially uninhabitable. So hopefully the pump wiring can be repaired to where it just comes back on after a brownout, which are common in the heat.
The neighborhood may concern suburbanites. It's the theatre district, but the side streets are nearly deserted after dark. There are trapitos (parking mafia, look it up) on this street because of the theatres along Corrientes, and there are people who simply sit on the street and drink all night. While they loudly greet acquaintances, I never saw them in any way harass anyone else, so we were fine going for ice cream after midnight. Tourists, Guerrin pizzeria is a block away, a required stop here.
Overall this is a characterful apartment perfectly located for subway access and restaurants. If you want spotlessness and guards in your neighborhood, you'll have to pay $200+/night for 800 sq. ft. in Puerto Madero. Stay here instead.