We stayed one week in Francisco's apartment with our son who was 18 months. We had a great time there, it was the perfect location for us. The area is wonderful and the flat very convenient. The bathroom and the kitchen are very big, and the balcony is wonderful, with a great view.
We just had to be careful with the stair and learn to use the stroller in the small streets ! We will definitely come back in Lisbon and in Francisco's apartment.