We spent 3 nights in Lisbon with this cozy apartment as our base. Maria is a very sympathetic host, we enjoyed meeting her. The apartment is not big, but more than adequate for a couple like us. If you're with 4 people it might get a bit crowded.
The location is superb: right in between most of the sights, a short walk to the first stop of Tram 28, to Rossio square, the Castelo, and several miradouros (viewpoints). There are great bars and restaurants close by, but after midnight the street is very quiet.