I cannot recommend this Izumi and Francis's place highly enough.
Our trip was thrown off a little bit because my boyfriend got a cold as we arrived in Sintra and they went above and beyond by offering to go and pick up cold medicine for us since it was a Sunday and no near by pharmacies were open. They were incredibly kind and accommodating far beyond what would be necessary or expected and I am forever grateful because it really helped us out a great deal. They also allowed us to store our bags after we checked out for a couple of hours until it was time to catch our train, which again was incredibly helpful and very much appreciated. As hosts I would give them 10 stars if I could, incredibly responsive to all of my questions and very helpful.
I was also very pleasantly surprised by the space itself, it looks lovely in the listing, but I was a little worried that we might feel somewhat cramped in the space as we are both tall and not particularly small people, but it wasn't cramped at all. The bed was a great size and comfortable, and they even provided extra bedding, which we utilized since we are both duvet hogs.
The garden is beautiful and we sat out there for a while each night enjoying the view and the fresh air in a quite private space.
It was pretty warm out while we were in Sintra, but it was always nice and cool in the apartment and we were very comfortable.
The location is also great, centrally located and easy to access the tourist information center where you can buy tickets for the castles and also a quick easy walk to the bus and train stations. And even though you are close to everything and the apartment is right in the heart of Sintra it was very quiet and peaceful at night.