It is very tiny, but it works very well for 2 persons. Especially, since you will be outside the most anyway. Also the small balcony area is very nice to have a place to sit outside for yourself.
It is a great location near the centre of Graca, which is very nice and also it has 2 of the best view points of the city within 5 minutes!
Going back is a bit of climb to the apartment, but for the prices we always used an uber, which is often cheaper than public transportation.