Check-in went well, Gabriel was very welcoming and explained the apartment and gave good advice about the neighborhood. I really loved my stay at the apartment. it was clean, it was tidy, it had about everything you can need (even a TV with Netflix!) and it was beautifully decorated. The location is great, within minutes walking of a lovely pizza & gelato place (called Insano), a viewpoint and cozy streets. During the night it's pretty quiet, which allows for a good night's sleep. When there was a little problem in the apartment, Rita came over and made sure it was fixed. When I had questions, Tiago answered them via chat. Everyone was friendly and helpful. The same goes for the driver, Paulo. He drove me from and to the airport.
All in all, I'm very happy about my stay here and I will come back in the future.
A little advice for groceries: Continente supermarket at about 10 minutes of walking distance has everything you need. A lot more options than the Mini Mercado.
Also, if you want to explore the city in a fun way and get free photos and video of yourself doing it: Book a photo bike tour with Loopitour. Most friendly and fun tourguide I ever met, she's fantastic. And it's a lovely way to get an impression of Lisbon.