Filipe's apartment is very clean, safe and comfortable. My wife and I stayed in Lisbon for over a month and Filipe's apartment was perfect for us. I would recommend it to family and friends staying in Lisbon.
The apartment highlights - excellent temperature control (has two thermostats); very good water pressure and temperature control; bed was very comfortable; apartment was cleaned and towels & sheets changed weekly; clothes washer is excellent and easy to use; dish washer available (we used it once), modern stove; all the appliances (toaster, coffee maker) and conveniences (wifi) are in excellent condition, easy-to-use and worked perfectly.
The best highlight is Filipe. He is a terrific host! He met us at the apartment when we arrived from the airport and gave us a very thorough walk-thru and orientation (explained how everything worked, recommended restaurants and provided details about the neighborhood). He checked in with us a couple of times during our stay to ask if we needed anything and how things were going. He is a fantastic Airbnb ambassador.
The Chiado apartment location is central - very near great restaurants, the metro and all of the top city sites. The Baixa Chiado Metro access is a one minute walk. As others have mentioned, in any city center location there will be some noise from the street. We did not find it to be a problem, but others may be more sensitive.
Overall, we were delighted with Filipe, his apartment and Lisbon.