We really enjoyed our stay in Nuno's apartment! He is a fantastic host, very caring and reliable.
The check-in worked out really well, he even tracked our flight so that he knew when we'd be there. For any questions he immediately replied and really cared for our well-being (however we still felt at ease like at home).
The flat is splendidly equipped. Kitchen has a dish washer, oven, gas stove, microwave, freezer, huge refrigerator, toaster, coffee machine and washing machine. When we came everything was there (such as coffee / filters, sugar, cooking oil, spices etc. but also napkins and detergent). Regarding crockery we didn't miss a thing!
The pool is a gem at hot summer days, with plenty of sunbeds and everything free.
When we arrived the flat was very clean and nicely smelling. The couch in the living room is amazingly comfortable and can be converted to a even more comfortable 2 person bed. There is also a TV with a set up box where you can watch a lot of pay TV channels (all in English with subtitles). So be aware that you don't spend to much time on it to not miss too much of Lisbon. WiFi worked smoothly.
As mentioned in the other comments, plane noise may be an issue. The building is directly under an airport approach corridor, where planes fly in low altitude from roughly 5 AM until 1 AM. With open windows you may not understand the TV for a few seconds, but with closed windows it's better (though still audible). For us it felt quite noisy in the first one or two nights but we got quickly used to it and then it was okay. Good point is, that there is zero car traffic noise! If you're not very sensitive to noise it should be no big issue. In Lisbon there a few places where you can't hear no planes at all, as the intl. airport is centrally located.
The location is decent and there is parking available. To get to other places in Lisbon, there are three bus lines directly there, which go to central locations like Sete Rios, Cais do Sodre and Ourique. To get to Sao Sebastiao (blue & red metro) you can either walk ~19 mins (hilly) or walk ~5 mins and take a bus. However, rides with taxi/Uber/Bolt are very cheap in Lisbon and we used it a lot (only ~15 mins to the Airport for instance).
About 5 mins walk away there is a smaller supermarket and 10 mins away there is a bigger supermarket with large service counters for fresh bread, fish and meat. Given the kitchen's equipment it offers to cook.
Else there are two traditional Portuguese restaurants very close. We can recommend "la Valenciana" which also has take-away for reasonable prices.
All in all I can really recommend this apartment! I'd say it's better suited for longer stays, given the not very central location and big size.