We had a great time at Paula's place. The self check-in was smooth and the itinary was easy the follow. The flat is in a great location, only a few minute walk from Baixa-Chiado metro station. The 4th floor is no joke, because you have to climb some steps to reach the top floor, but totally worth it, because the place is very comfortable for 3-4 person. It has a well equipped kitchen and comfortable beds.
However the flat has no built in heating system, but there are heaters and several blankets to make up the cold, and it is only applicable during the winter months.
All in all I strongly recommend Paula's place, it is a great start for a prefect holiday in Lisbon.