For the price of a basic hotel room (30 USD/night), I got a whole apartment! What a find! It was clean and comfortable, with all the amenities I could ask for. And considering the location (in the heart of the city), I found it to be very quiet. The internet works very well, the shower is hot and strong, and the kitchenette is equipped with a stove, microwave, fridge, and electric kettle.
The location is fantastic for seeing the most important tourist attractions, theater-going, shopping, and dining. First-time visitors to BA will find this to be the best location to explore the city. However, I didn't see much in the way of bars and pubs. For that, I think San Telmo is a better bet. San Telmo is also within walking distance, however, I wouldn't walk it at night.
Natalí is an exceptional host -- she's very responsive and gave perfect instructions for entering the apartment, so check-in was a breeze.
This was one of my best Airbnb experiences and I highly recommend it.