We stayed in Sintra for 3 nights and this was a great spot for us. Literally around the corner from the train station and easy walking distance to the National Palace and many, many restaurants, shops, etc.
Space was great for us. It's a pretty busy road in front, so there was a lot of road noise that went pretty late. Was our only issue. No air conditioning but the weather is super nice, so don't really need it. Hosts were great, check-in was easy and they even had a bottle of wine for us when we arrived - very tasty!
We already had our days pretty mapped out, but the did run into Guy and he was super helpful and offered several tips that would have been great if we had more time and/or didn't have our days already planned.
Great stay, great place, and love Sintra - definitely a must if you are in the Lisbon area.