I never met Arnaldo but was greeted by the buildings admin. I didn't received any checkin instructions either and had to wait until the apartment was ready and was able to reach Arnaldo.
The apartment itself is nice but it's suited for 4 people , the sofa is not for sleeping which made our fifth guest a little uncomfortable. The area is great for tourists as you're right next to the downtown and with a couple of blocks next to the subway.