The apartment is a great base to explore the city. The space itself was big enough for 4 of us (2 couples) to stay for a long weekend. The living space is large, two separate bedrooms and bathroom, it had everything in that we needed to cook a few meals and enjoy our time there when we weren't out exploring.
The location is also really great, up at the top of a hill but so are most places in Lisbon(!), and on the top floor of a 3 story building so lovely views. There isn't a lift so just something to keep in mind if you don't like lots of stairs.
Overall I couldn't recommend the apartment, and the hosts enough, they made our time in Lisbon really great and super easy, always fast to respond to messages, etc.