Bottom line up front: think twice before requesting a reservation. This property is one of those out in the market to make quick profit in a growing market, with complete disregard of customer satisfaction. We'd discourage others from dealing with this host (responsible for about 15 properties in Lisbon).
Check-in time was advertised to be available from 3 PM. Only after accepting our reservation request, the host announced that 6 PM was the earliest they would be able to check us in.
The only reason offered for this delay was that the host (who is not the owner of the apartment) needs to take care of her main job, with her regularly leaving the office way later than 3PM. In our opinion, the host should've openly disclosed this fact before confirming our reservation request.
After a number of confusing and dodgy messages, the host finally showed up after 7PM, with no keys to the apartment. She indicated that a locksmith would come in an hour or so... At this point we had completely lost our trust in the host and requested a cancellation of our reservation. She reacted very aggressively and left us in front of the apartment without clear indication of the way ahead. 10 minutes later we received a phone call from Airbnb staff. They were very diligent in helping us find alternative accommodation.
One last note in case you're driving into Lisbon: The area (and most of Lisbon actually) has paid on-street parking, limited to 3 hours from 9 AM to 7 PM. There's no nearby underground parking garage we could find.