Liliana's apartment is a very centrally located space to base yourself while exploring Lisbon. The space itself is compact, but beautifully decorated, which makes it quite a peaceful and pleasant place to be. I wouldn't stay a long time just because it is quite small, but its perfectly set up for a few days of exploring the city. The decor is modern but with gorgeous original features like window shutters and exposed wooden beams.
The one thing I would say - and it's not a reflection of the apartment, but the location it's in; while very central, it's frustrating not to be able to walk down the street without being *hounded* by the front of house restaurant staff and owners to try get you to come. It's borderline harassment - maybe it's the time of year and they're desperate for business, but we couldn't nip out for a few groceries without having menus shoved in our face.
But again, that's problematic of the area, and not the apartment. This is a beautiful space from which to base yourself for your Lisbon adventure!