Our stay here was a charm! Alejandro was kind enough to exchange some money for us on the first day, which relieved us from this task after our long flight from Canada. He was also extremely responsive whenever we had questions about other neighbourhoods. The apartment is very cozy and clean. The 2 AC units made it very easy getting through a hot week (30-35C). The pool is beautiful and carefully maintained every day by Gustavo. The other tenants are very nice yet quiet; they politely greet you when they meet you in the common areas but the general atmosphere is peaceful. 10/10!
One thing to keep in mind is that it is located in Constitución. It is a less affluent neighbourhood and some locals will tell you that it is unsafe. I personally find it more pleasant than San Telmo to stay in because there is no unwanted sollicitation of tourists while still being able to walk to San Telmo, Tribunales, PM and La Boca. I would think about it twice though if I were travelling alone.