The apartment is great. The location is probably the best to stay in Buenos Aires. You have everything within a walking distance and it's safe.
The place is fully equipped. It has washer/dryer in the building (there are also full-service laundromats close by, where they clean and fold as well).
The terrace is amazing, especially during sunset and the added bonus is the pool upstairs - which is private.
For me internet was the most important thing since I had to work during my stay, and it was really fast (500MBdown/40MBup - wifi doesnt reach the upstairs terrace)
Overall it was a really good stay, I'd definitely come and rent again.