We had such a wonderful stay in Lisbon and really loved our experience in Alfama at the apartment. What a charming area with little cobblestone streets and restaurants and Fado nearby. The apartment itself was very clean, and Roberto was a lovely welcome to let us in. I neglected to ask to have a second set of sheets and they were great about it and had someone come by to make up the couch for us. I really appreciated the prompt communication.
A few key things: you can't take a taxi directly to the apartment, you have to walk either up or down the cobblestone walkway (so a roller suitcase isn't the most ideal choice!). The restaurant downstairs, as others have mentioned, truly is wonderful--don't miss it! You need to be down there early for the first seating. Order everything, it's all incredible, and the staff are lovely.
The apartment is a great setup for a couple, but be aware that if you're planning to use the couch as a second bed it's not really meant for it and isn't the most comfortable.
Overall, love this place and you should definitely stay here during your Lisbon trip!