The apartment was really nice and clean, a lot of space and very well equipped. It is in the heart of Alfama, one of Lisbon's oldest neighborhoods which makes it really authentic and unique...and it is close to the city center. Further, Francisco is a nice and helpful host and replied immediately if we had questions.
To sum up: Lisbon is great, the apartment is ideal and I would recommend and come back myself at any time!
(A tiny minus: the wifi is not the best, but can be compensated by having a nice drink at the bar - with wifi connection - nearby ;-))