The apt was as described and illustrated. It was clean and comfortable, nicely laid out and in a quiet and safe neighbourhood close (5-min walk) to Metro Rato. Many places of interest are within walking distance. The bed was comfortable and the bedroom quiet and dark. Samuel checked several times to make sure all was well. A bit of advance explanation about the keyless entry / self check-in would have been helpful (I wondered why no info on check-in was provided until 2 days before arrival). Although not AC, the apt was cool (it has very thick walls and good-quality windows). It did get a bit warm and stuffy on hotter days (see below re windows and ventilation). The doors and windows lock securely. TV has a mix of English-language and local channels and the WiFi was high-speed and worked well. The bathroom is large with a nice, walk-in shower, and there were no issues with hot water.
As indicated in the description on AirBnB, the apt is at ground level. It has 2 modern, dual-pane windows opening directly onto the street, at heights of 1 - 1.5 m above the sidewalk. When the windows are open to allow in the cool evening / morning breeze, there was no barrier (such as bars) and anyone could easily enter the apt directly from the street. It is acknowledged that the windows can be tilted open a small distance at the top, but not enough to allow useful ventilation. Some sort of exterior bars, decorative grill or heavy wire mesh would alleviate this concern, at the same time allowing better air circulation into the apt.
Notwithstanding this concern, Samuel & Carla's apt is very comfortable, well equipped and well located and is recommended for your stay in Lisbon.