Excellent location, with easy access to the historical centre of Sintra and (relatively) easy access to the park of Pena and the moorish castle.
We stayed for a week, but probably is more suited towards shorter stays. The kitchen is tiny and there are low ceilings throughout - so watch your head! The only internal door is to the bathroom - not the kitchen or bedroom, so if you want any privacy between guests you're not going to get any.
Communication was Mariana was excellent. She let us check in a few hours early and was over within an hour of us having a power cut. We requested a chopping board and kitchen knife as they were missing and she dropped them over the following morning. Much appreciated! And she left us some free cake from Piriquita in town.
The property is next to a main road into town so there is some noise during the day but in the evening is empty as the bus loads of tourists have finished for the day. The neighbours above or next door (unsure which) are quite loud and did keep us up on a couple of occassions so be wary.