Alzerina's place has a phenomenal location. You're just a couple of steps from Copacabana Beach; her apartment is incredibly close to the beach and every thing else a good neighbourhood offers. There are two train stations at walking distances, a great number of bus lines just one street down from her house and easy access to other incredible places in Rio.
Alzerina is very practical, welcoming and kind. She helped me with tips and guidance all the times I needed and certainly made my stay in Rio outstanding.
The room I chose was the smallest in her apartment, but with the ceiling fan and the door open, I had no issues sleeping; there's a window very close to the room, so there's a good amount of air flow. If you don't mind small rooms, that's a safe bet. Plus, there's a bathroom really close to you and good, spacious drawers for you to keep your belongings.
She'll give you a copy of her place's and your room's keys, which grants you even more security. She is adorable and really open to receiving guests at her place. A must-visit :)