We spent a week in Martin's apartment which is cozy and very small, but it has enough space for two. Before we started our trip Martin gave us a few tips how to get to the apartment the best. Because of the winding streets in Lisbon, we first had some difficulties finding the apartment. But the communication was uncomplicated and quick so Maria just picked us up in the streets and took us to the apartment.
Towels, hair dryer and a few maps were available. But the best thing for us was the air conditioning.
The neighborhood is charming and not so touristy. Everything in the center of Lisbon is within walking distance. Otherwise the metro, bus and tram (also the line 28) are about 5 minutes walk away.
For a trip with two people, I would recommend the apartment at any time.