ABSOLUTELY RECOMMEND THIS!
We had a wonderful stay at Rui & Elsa‘s place. We booked it spontaneously because we couldn‘t stay at our first accommodation, but within a few hours the check-in was ready on the same day we booked the flat, and we were absolutely happy about it. The flat was clean and super comfy and there is enough room for six people. Two of us slept on a sleeping couch but it was comfortable. Rui & Elsa responded immediately whenever we wrote them and we had a wonderful time in Lisbon. The only issue was that there were some other travelers in the flats downstairs and they were a bit too loud in the evening. But after telling them to be more quiet they decreased their noise, so it was fine.