The flat was as advertised: clean and conveniently located for walking in Sintra and the surrounding countryside. The host provided several nice touches: port for us to sample, pamphlets for local attractions, and fresh towels midweek. We had a lovely stay.
There is only one concern: Unless you plan to park your car for the duration of your stay, navigating the streets and finding parking can be problematic due to the changing traffic patterns. The hosts saved us a public parking space when we first arrived, but it is unrealistic to expect them to do that if you plan to come and go as we did. If you plan to go further afield, it is better to hike or take the train.