I stayed a week in the apartment and it was great. The view is fantastic, almost 180 degree, your able to see the bridge, the Tajo and the Atlantic (+ amazing sunsets & night views).
Ajuda, the neighbourhood, feels original Portuguese, with everything you need (supermarket, cafes, restaurant). Bare in mind that you're staying in an outer district of Lisbon. The metro (Belem) is ca. 15min down the hill, but there are lots of bus and tram stops around the apartment. Lisbon buses are not always the most punctual or fastest though.
If you want a calmer stay in Lisbon with a great view, the apartment is perfect and has everything you'll need.