This place is as central as it gets in Lisboa. Be aware that you will hear the tram early in the morning, all day and late in the evening (not at night).
It is wonderful to walk down one floor and be right in the middle of everything.
Subway, underground parking, storage lockers, tram, bus, rental bikes...all there.
You can also explore lost of the city by foot from there.
The description is very accurate. I have nothing else to add.