We had a great week in Lisbon! The apartment is beautiful and Samuel was very helpful and quick in his replies. The location is perfect, we were able to walk pretty much everywhere and stations to go to Sintra and Belém are also close.
We definitely recommend the apartment!
There are a couple of things we noticed though: the bathroom is very narrow (you shouldn't be very overweight!), also the apartment only has an electric heater and isn't very well isolated --> it’s rather cold in winter. On the other hand this is very common in Lisbon and only December, January and February are that cold. Last thing, the door to the building gave us some trouble, you need to shake it a little while you try to turn the key.
All in all these were minor points though and the pros strongly outweighed the cons.