We were three guys and we decided to rent Mariana's flat because she has the best comments. I must admit they are right! The flat is amazing. It has one living room (TV/Cable) and two bedrooms (all with air conditioner), also, it has three bathrooms, one kitchen and a laundry. Also, the bulding has 24 hours security. Actually, the apartment is very complete!
Mariana's mom, Dede, was waiting for us, she is very sweet, she explained us all thing about the flat, including how to use the washing machine. :)
Also, she gave us a gift and she left some beers to us as a welcome.
Besides, Mariana contacted us, explaining what we can do in Rio what places, disco, bars, etc.

To summarize, the apartment is great but the hosts are much better!!! Sincerely, I recommend them.