Location made it all - it's walkable distance to any spot in the city (if you're not scared of the hills). It's not in the middle of hot tourism like Alfama or Chiado, but not in remote residential areas either. Principe real is a well-balanced combination of tourists, expats, digital nomads, and locals. Did I already mention you can walk anywhere in the city from there? :)
The apartment is recently renovated, so it's neat and clean. Although it's located on a rather heavy traffic street, it's pretty quiet in the apartment due to double-pane windows. The kitchen is new and well equipped which comes handy for long-term staying. The internet speed is great, so we were able to work during our almost two month stay with no issues. There are plenty of amazing restaurants and bar close by.