We stayed here for a week. The best part about this apartment is the location, walking distance to all the places you would want to visit, as well as metro and the main train stations for easy access to Sintra and Cascais. We also found many great restaurants within a 10 minute walk. The other great feature is the balcony, with a panoramic view of Lisbon from the Castelo Jorge to the river. We also had a car, and were thankful for the parking space (which is very small). But we did not use the car at all while we there, given easy access to all of Lisbon by walking or public transportation.
The apartment itself is on the top floor of a small building with one apartment per floor. Access is through the small garage which brings you to a stairwell and elevator area. The apartment is three floors up, but we used the stairs most of the time. The elevator was operational and convenient for transporting luggage.
Each room in the apartment is on a different level, which we found quaint and somewhat eclectic, but because of the stairs connecting each level, this apartment may not be suitable for small children or those with difficulty traversing stairs.
The apartment is well-equipped with everything you would need, and communication with the hosts was timely. We had two minor issues: First, the building next door is under construction which may be an inconvenience because of the construction noise between 8am and 6pm during the weekdays. This is completely out of the control of the hosts, but if you are planning to work during the day (as I did), the noise was a nuisance. We did not observe any construction activity on the weekend. The second issue was the hot water in the shower, which was inconsistent. At best it was lukewarm, while the water from the sinks was piping hot. Other than these two issues, I highly recommend this place.