The flat was great, clean and well located. We were in the heart of the old town with nice view to the cathedral and the river. The neighborhood is nice too with few little cafes, restaurants and fado/jazz bars. Getting into town was easy too through the 28 tram, which in itself is a good experience (not in peak hours). If you take the tram further up the hill, you will have a great view of Lisbon.
Daniel & Leonor are good and reliable hosts. They prepared for us some tips on how to get around and make the most of your time in Lisbon. That was very kind.