I havent met Paulo & Camila, but their friend Nunno was really helpful to explain the city/stuff around.. I havent seen them later on, but I didnt have any issues as well..
The house is close to bairo alto, takes 10 min to go to baixa/chiado metro station, though the roads are hilly.. might be difficult if you have a luggage and using metro for airport. and taxi costs 30euro.
there was a construction noise around 7:30am every morning. although it is nothing to do with the owners, just be aware of that if you would like to sleep more..
overall, the house and the location is on average..