I stayed in Fátima's apartment for a week in September. I made the reservations rather last-minute but it turned out to be a great location, right off of a lively pedestrian street within walking distance of both the waterfront and the Sao Bento station. There are tons of wonderful restaurants and shops near the apartment, and though it is located on a somewhat noisy street (lots of street performers which was great!) since the apartment is at the back of the building it was really quiet. If you're a solo traveler or a couple the apartment is a very good choice - just enough room to be comfortable.
My only hesitation is that if you're planning to work remotely, as I was, the wifi might be slightly less robust than you might like. Fátima was super responsive to questions though, and when I mentioned the wifi she immediately provided me with an alternative that was much improved in terms of upload speed. I did end up jumping around from the apartment wifi to the alternative wifi and my mobile hotspot though, depending on what I was working on.
I gave this apartment five stars, because it is comfortable, well-located, well-provisioned, affordable, and the host is very communicative.