I stayed for three nights and had an absolutely wonderful time. Bruno & Ines are seriously the perfect hosts and genuinely awesome people, I felt right at home. Their son is a sweetheart, too.
The location is really good, you can walk to pretty much all the important sights. The bed is comfy and the room is quite big.
I really enjoyed my time in Sintra, if you come, you should 1000% stay here. :)