We stayed at Ruben's place for several weeks as we were living in Lisbon for two months. He was a great host, always made sure we had what we needed, regularly cleaned the place, and was very accommodating when COVID-19 made us alter our plans.
The apartment itself is in an amazing location, just a few minutes walk from Cais do Sodre, Bairro Alto, and Praca do Comercio. For a stay in Lisbon I highly recommend staying at this spot!