I had a long term stay in Nico's apartment for various months. I loved the apartment! It is so spacious and had everything I needed. It is hard to capture in pictures but the ceilings are about 15 feet tall including in the hallways. The building is grand. Every room has a different wall pattern and feels unique. There is a building manager there everyday that cleans everything and is super friendly. I was a bit concerned about safety based on my google searches but the area turned out to be fine. In fact, I appreciated being in the area because it felt less blatantly touristy than others (eg. Palermo). The immediate vicinity by Congreso is full of bus stops on every corner and there's always people on the streets. The subway stop is a 1 minute walk from the front door. Taxis come down Rivadavia by the 10's - it never took me more than 30 seconds to hail one down. I saw some reviews that said there was a nightclub downstairs but when I arrived in January 2020 it was no longer open. - never had any trouble getting any sleep.
Unfortunately, Argentina closed its borders while I was there and I had to leave. Nico provided me a partial refund and sent his sister to check me out with a few hours notice. I really appreciated his help given the stressful situation I found myself in. Overall, I would have still picked this apartment had I known what would transpire. A true gem!