Helena's place is maintained well and near to the place of attractions. There are some small shops to get your groceries and there are plenty of local restaurants nearby as well.
The apartment is located on the highest level of the building. You need to know this if you have heavy luggage. However, the staircase is quite wide so it was not really a problem to bring the luggage up. The road leading to the building is pretty steep if you go there from the metro (the nearest is Anjo station).
Being on the hill, the building gives you a nice view of Lisbon at night. Really nice to unwind when you reach the apartment at night.