Luiz is a very friendly, helpful guy. He let me check in a little early since I had an early flight in, and check out late afternoon since I had an evening flight out and the apartment wasn't rented that day. He also promptly fixed the shower when there was no hot water and when the toilet wouldn't stop flushing.
The apartment is well located in Centro, just 400 meters from the Cinelandia Metro station and the Municipal Theater, and lots of nearby restaurants, although most of them are closed on the weekends. The apartment is fairly small but comfortable enough for one or two people; the bed is very comfortable, and the small refrigerator is adequate. The kitchen is very small but sufficient to heat up something on the stove or in the microwave. The bathroom is fine, with a good shower, and some racks to dry any washing you may have done.
There are three issues with the apartment, which could range from just irritating to a serious negative, depending on how important they are to a prospective renter:
1) The apartment is on, and the window faces, Rua Evaristo da Veiga, a very busy, noisy street, with lots of bus and car traffic. Even though the apartment is on the 18th floor, you can hear some noise, even with the window shutter closed, at all hours, although the air conditioner drowns out most of it when it is on;
2) The TV is old and there are no international channels, only local Brazilian channels, half of which cannot be seen because of bad reception and none of which are of any interest to a non-Brazilian, so you will not be watching much TV if you are a foreigner;
3) Given the TV situation, good Wi-Fi is even more important; however, the W-Fi in the apartment, while good when it is working, shuts down and restores itself at random, which was frustrating, and sometimes the router had to be manually turned off and back on again when the Wi-Fi didn't restore itself. Luiz is aware of the problem but apparently nothing can be done about it.
Given the location, the apartment features, and the price, I would definitely stay here again and can recommend staying here if the issues described above are not important to a potential renter.