Pros: The apartment is small but is quite comfy and has a working kitchen which is very nice. everything was well kept and clean. The balcony is nice to sit and eat and look out over the city.
There is a bus stop right next to the house which brings you to the zoo and a metro station.
The airport is very near and easy to get to and from.
Communication was easy and swift, Maria was our contact at the place itself. She was friendly and put effort into ensuring that we have a nice stay.
Cons: We were told we could park in the street with our rental car. As the whole area is residents only we got 2 Tickets despite that first assurance. We don't yet know for sure if we have to pay the tickets or not. I would not recommend getting to the apartment with a rental, just take the metro or a bus and walk a bit.
As others noted, the airplanes touch down not far away. they fly low over the apartment for most of the day so it is quite noisy. Especially in the evening/early night that could be an issue if you go to bed early or want to sleep into the day.
The distance to get to the next metro by foot is quite long. Expect a 30-40 minute commute to get into Alfama by public transport.