Excellent location to tour several sites around Sintra. If you are driving try to play your check-in later after 1800 hours to pretty much guarantee you can get a parking spot right by the apartment.
Quick and easy instructions to get into the apartment. The place was clean and well stocked. Pedro also provided excellent information on local attractions.
We were able to walk to the Moorish Castle and all around Pena in one day. We were also able to walk to Quinta da Regaleira and Palace of Monserrate on another day. If you don't want to hike it out to Monserrate, there is a fair amount of parking there, or you could take the bus.
You are above Villa 6 so you will hear some noise from below if you are home. Don't worry, they don't stay open too late. We do recommend eating there at least once. The octopus was fantastic. It is also a quick walk to Fábrica da Nata which is another must.
Hope this helps.