The three of us had a great stay at the apartment and felt just like at home. The location is perfect as we could reach everything on foot, there are also a lot of restaurants and bars nearby.
The flat was very clean and with lovely decoration. We were picked up by Gustavo at the airport and brought to the flat (which hadn't been cleaned at the time as we arrived at 10am, but it was no problem to see the apartment and leave our luggage there, which was a great plus for us).
I would totally book the flat again when in Lisbon and do recommend it to everyone!