Great apartment. The location is very unique. The Travessa is a drivable street at the top of the hill, but where the hill becomes too steep, it becomes pedestrian stairs, then resumes being a street. The apartment is in the section that is blocked to cars (the stairs).
The area at the bottom of the street has popular bars. During festas, the DJs until 2AM and partying in the street until 3AM was remarkable, but with the option to close the windows and shutters and turn on the A/C, noise was not a problem for me at all. Also, one night, I had a friendly Lisboan in a panda costume give me a free beer on my way home. Your mileage may vary.
The location is perfect for exploring the city, one block from multiple streetcar lines, and walkable distances to many historic sites, gardens, the Roman aqueduct, the public market, waterfront, etc. This is a great place to settle in and experience the city.