I booked the room in Guilherme's house for a week and ended up staying for a month..
The room is in the ground floor of the house, in an apartment which is shared with another guest.
The apartment is quiet, clean, cozy, nicely decorated, and the room is spacious with a comfortable double bed.
From the garden around the house one can enjoy the view of the Pão de Açucar.
The location is very convenient because both Glória and Catete metro station are within less than 10 minute walking distance (Glória metro is the closest one), where one can also find supermarkets, restaurants and shops. The area is safe both during the day and at night.
Last but not least, in only a few minutes one can reach the Aterro do Flamengo, if you want to go jogging, cycling or just enjoy the beach.
Guilherme and Juliano are very easy going hosts and always ready to help. They will both respect your privacy and invite you for dinner if they are having a barbecue with friends. :)
Thus I definitely recommend Guilherme's room/apartment for both short and long stays in Rio.