This flat definitely has the best view in Lisbon. The view alone makes it worth it.
Pros: view, comfortable double beds in separate bedrooms, good linens, full kitchen. Very spacious and well appointed. Right by a scenic view point. Hosts left us a phenomenal bottle of red wine and some cheese in the fridge. They were very accommodating with our early arrival and let us drop our bags while the flat was cleaned from previous visitors.
Cons: the scenic view point brings a lot of tourists, so it can be crowded and is usually a bit noisy by 9am. The church bells start at 8am, so between that and the tourist traffic don't plan on sleeping past 830. You will have to do a decent amount of walking to get to the rest of the sites, but it's easy and there's always uber. The only semi-frustrating thing was lack of timeliness: delayed response time, an hout late for airport pick up, and late to let us into flat.
Overall, a great place to stay and I can't say enough about the view!