The flat is Very Well located. It's like 1 minute from Ipanema and 5 or 8 from Copacabana. If you are looking for the sightseeing and not just the beach you can take the metro with a walk of just a couple of blocks.
I stayed there with my family for 4 days on a budget buying at several stores around. The kitchen is helpful because the city is really expensive.
We didn't stay in touch with Valeria, tough she was available and ready to help.
Summarizing: it's a good deal and a good option in a mesmerizing city.