What a fantastic place!
The location is extraordinary; walk far from lots of restaurants, bars, the Time out Market and many of the "must see" attractions.
It is also walk far from the Cais Sodré, where you can catch the train to Belém, Sintra, Cascais, and many other cool places.
Also, it is only 45 minutes by public transit from the airport.
Moreover, it is a 5 minute walk to the Miradouro Santa Catarina. My wife and I had daily quiet breakfasts and not so quiet sunset drinks there before heading to everything Lisbon had to offer.
The owners are very responsive, and the whole process was smooth.
A great extra is the Cafeteria Nando and market that is literally in front of it. The owners are the most caring and polite people you could ask for. It is very convenient having this access.
We had an amazing time during our stay and I am sure you won't regret booking it.
Cheers