Absolutely loved my stay at Rita & Helder's place. It was super clean and had everything we needed (AC, washer, iron, kitchen appliances, hair dryer, etc.). We were welcomed with a few fruits, Portuguese egg tarts, and a small wine which was such a nice gesture. It was also very easy to communicate with Rita & Helder, they were super kind and attentive. We had a lengthy stay so they asked if we wanted our sheets and towels changed - really awesome. I honestly have no complaints.
The only thing is as others have mentioned the apartment is located on a street that can get pretty loud, but it quiets down around 10:30ish (a bit later on the weekends). The reason being is because you are located above many restaurants, the usual street performer (playing music/singing), and souvenir shops. That being said though, it's totally tolerable because you're also out there enjoying the city or just chilling in the apartment. I was personally cool with the noise and nothing beats being in the heart of Lisbon (you're literally close to everything). Overall - I highly recommend staying here!!