We had a really nice stay at this apartment. The location was perfect, very central - we visited most places by foot. We loved the area as it is close to many historical places and to the famous Santa Lucia view point.
The check-in and check-out was extremely simple too. Concerning the apartment, everything was as described on Airbnb, very clean and super well-equipped. The hosts are well-organized and explained everything we needed to know for our stay via e-mail.
Only remark: the window's aren't very soundproof so it can be a bit noisy during the night, as the area is well visited also during the nighttime (also: apparently it is a normal thing in Lisboa for the garbage collection to happen around midnight - you might want to bring some earplugs).
Overall we had a great stay at the apartment and would definitely recommend it for a touristic trip to Lisboa!