The apartment is exactly as advertised. It is clean, spacious and comfortable. Margarette is genuine, and extremely helpful. There is 24 hours security/door attendant, and there is keyless entry into the apartment.
As a reference point, the apartment is near the JW Marriott, short walking distance from the beach, restaurants, and shopping. The area is safe, you can find bars, entertainment, and an active nightlife in the vicinity.
I was happy with my selection and would recommend this apartment. I will definitely stay here again on my future visits to Copacabana.