My fiancé and I spent five nights at João's flat and were pleased with our stay! His space is located right next to the Castelo de S. Jorge which is a prime location when visiting Lisboa. It is also just a walk away from many restaurants, bakeries, cafes, wine bars, and beautiful view points. It is about a 20-25 minute drive from the airport.
The flat is clean, charming and quaint. It is fairly small, but comfortable. Although it is located right by the castle where there was constant hustle and bustle, sound was never an issue since it's on a street with no car traffic.
Joãn and Silvia, the concierge, were both very kind and easy to communicate with. They both made themselves available to answer any questions and were prompt with their responses (via both Airbnb and WhatsApp).
I highly recommend staying here when in Lisboa! My advice is to pack your walking shoes though because there's a lot of hills and steps around where you’ll be!