The location is fantastic, the street is quiet considering where it is in this popular area, and the apartment was a great size for the four of us (2 adults & 2 kids). We had a great time in the neighborhood! Chiado and Bario Alto are full of great cafes, restaurants, bars, music places, and historical sights and very walkable.
Keep in mind that the apartment is on the 2nd floor (no elevators) and has no air conditioner, but neither of those things bothered us much.