First, about the host. The word "Super" might not be enough. Luiz Antonio went out of his way to help with anything and everything, from computer problems to where to eat to getting my return covid tests. ABNB needs to invent another word for this host.
About the apartment, it is as pretty as the pictures and bigger than appears in the pictures. The bedroom could easily have been made into two, and the bathroom is not the typical barely squeeze-in type you sometimes find in Brazil. Everything was spotless, bright, and airy. The kitchen is well equipped and the washer-dryer was very appreciated near the end of a stay. The furniture, mattress, and appliances are fairly high-end. While the decorations are lively, I did not find them to feel cluttered. There was plenty of surface area for me to spread out my own stuff without bumping into or knocking over any of the owner's stuff. The best thing about staying in a hosted apartment is experiencing the domestic quirks of living in Brazil - how people hang their clothes (ingenious lines dropped from the ceiling), open their windows (ingenious sliding, flipping panels), light their closets, filter their water, etc. Yes, Luiz Antonio had to explain a lot of things but it was all fascinating.
As for the location, the graffiti and street people might put off the overly squeamish, but it's not as bad as it looks, and it looks like this in much of Brazil. The apartment is at the intersection of Santa Teresa, like a pretty colonial village on a hill (not a favela), Lapa, the 24/7 nightlife neighborhood though even grittier, and a string of pleasant, lively, regular-folks neighborhoods to the south (Gloria, Catete, etc.). I find these to be at least as nice and interesting to stay in as the beach neighborhoods and considerably safer, as they are not typically full of tourists to prey on. Just walk for an hour down the single winding street connecting these neighborhoods and you'll find them chock full of restaurants, juice shops, corner stores, parks, colonial mansions, churches, a palace or two. In such a beautiful city with so many world-famous landmarks, many don't realize that there is even more to be discovered in Rio.
The apartment is only a few minutes from a metro station that will take you anywhere and very close to the domestic airport. You can walk there in about 20 minutes if you don't have much luggage, though you'd have to navigate crowded streets.