Great spot very central in Estoril - we used it as a landing pad for trips within Cascais and it would be good for Sintra too. Its a very quiet neighbourhood, and you have your own private terrace to enjoy coffee in the mornings. Good hot water, laundry machine, reliable wifi and plenty of space in the triplex plus parking, which is very hard to find.
The only thing is it was a bit cold in the winter - as many homes are in Portugal - but we wore sufficient layers to combat this. At night there is a heating function on the AC which was sufficient. Again, that's really the only down side of this home if you are coming during the cold month.
Cristina is very responsive, and was accommodating when our flight was cancelled and we were delayed coming in.
There are restaurants, supermarkets and all the necessities right outside the house too.