Location, location, location! Paulo's apartment is in beautiful Príncipe Real and central to everything! The apartment is on the ground floor on a very quiet street but within a few minutes walk from all the action of this vibrant neighbourhood including dozens of amazing restaurants and bars, Príncipe Real garden (beautiful park with different vendors depending on the weekend), and the famous Miradouro de São Pedro de Alcântara. Barrio Alto is a 10-15 minute walk and Rossio Square and Avenida da Liberdade are also within walking distance. If you don't feel like walking, main routes for bus, tram, and the metro are really close. There are many nearby shops to pickup essential groceries. The apartment is small but has basic necessities and has an air conditioner and washing machine which we made good use of during our month long stay. There were a few minor things that needed some small repairs such as a chipped/cracked floorboard (we let Paulo know this). Wifi is great and fast.
Be aware, the building itself does have a "musty" smell which was initially in the apartment unit but dissipated once we opened the windows and let some fresh air flow through. Don't let this put you off as this is very common in many Lisbon apartment buildings due to their age. We saw a cleaning service in the building regularly, keeping the common areas immaculately clean.
Overall the apartment unit is clean and very tidy. Though for my personal taste the bathroom could have been cleaned more thoroughly as I did find a stray hair on the floor. However, this is a cleaning service issue that can be rectified. This is the only reason I gave the cleanliness category 4 stars.
Communication with Paulo was excellent. He answered all my questions promptly. He even picked us up from the airport. He is very personable and helpful.
With a few small improvements, this will easily be a 5 star apartment in every category. We would stay here again and recommend it.