Filipe is a great host: considerate, flexible and spot on with communication. Apartment is located within walking distance from the city centre, but we were driving nevertheless (no problem with parking outside the house).
The apartment was clean, had all the amenities and our room had a decent view (you could see one of the castles from the balcony). The only thing that was a bit bothersome was the only bathroom that's shared among 4 rooms (8 people in our case). At peak times it was a bit of an issue. Outside of that and a squeeky bed :) plus considering the price it's a good option for travelers on a budget as accommodation in Sintra can be a bit expensive.