Great place with fantastic views from the balcony. I would book this place for summer in a heartbeat with that nice hammock. Amenities are thoughtfully placed, would be great if there's dryer for winter. Great location with a metro station close by, however vulnerable travellers should consider the socioeconomics of the area. Overall really happy with this place, I'd say the beddings/comfort level is as good as your hotel chains. Highly recommend this place!
P.s. Camila gives great recommendations as to what to do/see in Lisbon. Get in touch with the hosts early if you like to plan your holiday!