Everything was great! Communication beforehand was super easy, Gonçalo was there for the check-in and even helped us to carry our luggage up the stairs which are a bit narrow. He even had fresh Pasteis de Nata ready for us! The flat was super clean and spacious, nicely furnished, and had a pretty good view over the city. It also had everything you need and more, especially a very well equipped kitchen. We also got a lot of recommendations for restaurants in the surrounding areas and other parts of Lisbon. A lot of bars, restaurants and shops can be reached within a few walking minutes.
Side note: We "accidentally" also rented another one of their places in another area, which was equally great!
All in all could not have wished for better hosts - 100% recommendation!