The apartment is located in a pleasant residential and authentic neighborhood with restaurants, supermarkets and pharmacies nearby. There are plenty of options for public transportation if you don't want to walk much, but in our case we walked most days to various tourist sights without any problem.
Joao and Sandra are extremely nice and responsive. They even had a lovely Portuguese small meal waiting for us as we arrived from the airport in the evening.
I would definitely come back to this apartment and recommend it to anyone who is looking for a great place in Lisbon - and the view from the living room is so beautiful! We spent 2 very pleasant weeks in Lisbon, and their apartment was a big part of that.