The apartment is very nice and has amazing view.
I would recommend it for 2 adults and 1-2 kids, or maybe 3 adults. If you have more people, you just won't feel comfy given 1 bathroom and the size of the space.
I would also recommend everyone to do their research on the area you wanna live in. This one is great if you want to get the authentic Lisbon feel. If you want to be really central - go to Baixa.