We spent one week in the flat. It Was perfect. The flat is provided with everything, really confortable and well located. The area is quite calm at night, no pb for sleeping and if you want to go to Bairro Alto it's just 5-10mn walk. There is a supermarket really close to the flat and you can take the tram 28 really easily as there is a stop down the street.
Andrea was really nice, available for any question or advice and he help us to solve some problems rapidly.
I Will definitvely recomand this flat and its hosts.
Enjoy Lisbonne!