I've stayed for one month in Celia's apartment and I've had a very good time.
The main asset of this apartment is its excellent location: near the lively Praça General Osório and its metro station, and less than five minutes away from Ipanema's beach.
Celia was friendly and helpful. The building feels safe and the apartment was clean and equipped with everything I needed during my stay.
Only the sound insulation of the sleeping room could maybe be improve. But it is already fine, there is not much traffic in the street below.
Overall, I highly recommend this appartment.