This apartment is very convenient for exploring all the sights in Alfama and it is just a 20-min walk from the centre. As others have already mentioned, it's not suitable for people with walking difficulties as there's no elevator (the apartment is on the 3rd floor) but I have a feeling that all the buildings in the neighborhood have the same problem. Get in touch with the hosts if that's an issue for you and they might be able to recommend something else - they are really good in responding. The apartment is super clean and neat, bit smaller than the photos, the ceiling on the top floor very low, beds super comfy and the view from the small balcony very rewarding.
Overall we had a great time there.