We stayed with my wife and two boys (1,3yrs). Once we had moved all the lovely books and lamps into safe higher spots, the place was a great base from which to explore Lisbon.
A fantastic apartment in a great location. You're in a very quiet and safe part of town, just behind government buildings. Great ammenities and park nearby for kids, centre of town is a 15 minute walk away. There is an old classic lift to access the apartment which seems odd at first but becomes very normal very quickly.
Highly recommended.