Sergio really is the best host, extremely kind and helpful and his english is great!
The location is nice, with the center of Santa Teresa on walking distance and a bus stop just in front of the apartment. The closest metro station is around 20 minutes by foot, with quite a steep walk going back. Lapa, the best party neighbourhood, is also within walking distance.
The apartment looks like the pictures. The shower is great and there is a washing machine you can use for free. The bed was a bit of a bummer though, since it is just a small layer of foam on wood. The kitchen lacks proper equipment for cooking a normal meal, but Sergio was talking about getting some new pans.