This place is a gem.
In our group: 2 parents and an 8year old. First time in Lisbon. The apartment is really well located if you don’t want to be smack dab in the hustle and bustle but close enough to walk places and hop on the metro at Rato station which is about 50 steps away.
Principe Real has a more relaxed vibe than Chiado or Baixa, from what I could tell.
We spent a lot of time at a nearby (10 min walk) park called Jardim Guerra Junqueira/ Jardim da Estrela. Peacocks. Cafe kiosks with food and drinks. Playground. People working out. Amazing plants. Worthwhile. A local gathering spot.
The apartment itself: comfy beds. Really great living room to lounge around after sightseeing. Great art, great decor. You’ll need to bring kitchen cooking basics if
you plan to cook. No oil, etc. bring coffee too, or pop downstairs to the small cafe and have an espresso.
Great checkin and communication.