Benjamin's place is nice. It's clean, well equipped and in a good location. Benjamin himself was extremely helpful and gave us good advice about things to do. Alfama was a great area to stay in and is definitely worth exploring. It took us maybe 10-15 minutes of walking along nice streets to get the centre of the city. I can definitely recommend staying in this apartment.
My only caveat is that the stairs up to the apartment are extremely steep. It's only one flight of stairs, but this could be a problem for anyone who has trouble with walking.
Thanks, Benjamin!