We only stayed for 1 night in Luis's apartment but I really wish we had more time there. The apartment is in an excellent location, just on the east side of the main part of town so everything is really accessible by walking. Even though it's in this central location the apartment is incredibly quiet. The glazing on the windows does an amazing job at keeping noise from the street to an absolute minimum. It is clean and more importantly really comfortable. We had a good nights sleep as the bed was big and comfy and for the first time on our 10 day trip to Lisbon we had decent pillows!
Communication was good, and Luis and his team were extremely accommodating as they arranged for us to have an early check-in.
I would HIGHLY recommend staying here if you are looking for somewhere to stay in Lisbon.