Lisandro's place is a nicely laid out, comfortably furnished, 1-bedroom apartment in a well maintained building in a great part of town. I found it to be very clean, with a comfortable, moderately firm bed, a good desk with plenty of working space, and very good internet (in the 30 mbps range with no service interruptions in the 7 weeks I was there). The kitchen had a nice selection of basic cooking equipment, and the water heater provided plenty of hot water, very quickly, to the kitchen and bathroom. The tub in the bathroom was larger than average, and served as a good soaking tub for long baths. There was a nice balcony, with a terrific view over some low buildings, across a large park beyond them, and out to the river. There was good airflow through the apartment, and while we did have some warm spring days while I was there, I never needed the A/C. And while I'd occasionally hear neighbors in the hallway, I heard little or no noise from the apartments around me.
The location is right in the middle of a very nice part of the city, with lots of shops and restaurants around, museums and a couple of decent malls in walking distance, and quite a few international embassies. The metro stations are a bit of a walk, depending on which line you need, but I found them convenient, and the nearby major streets make bus and taxi access easy. The apartment does get a fair amount of street noise, and I'd recommend earplugs and/or white noise apps at night, but that's true of a lot of Buenos Aires. The neighborhood is very safe, and there's a 24-hour doorman for the building.
Lisandro was a delightful host, very friendly and with excellent English, and he was very quick to respond to my messages. He was a sincere pleasure to interact with.