The apartment is absolutely perfect for a short stay in a city. Good location - the downtown is a 10-15 minutes walk, no need to use the public transport to reach many of Lisboa attractions. Vera and Joao are friendly and helpful hosts.
Cons: The apartment is on a corner - while there is heavy traffic, it is noisy - but during the night the noise is reduced strongly. As it is on ground level, if you don't want the people to watch you, the curtains must be always set (? I don't know the perfect word, excuse me :-) ), so the apartment is dark. It is not a real big problem for a tourist, who is in the city from morning to evening.