This is an excellent Airbnb. The apartment is clean, pretty and well layed-out. I was comfortably able to work remotely during my stay using the desk.
Alfama is a little touristy, but the centrality of the location makes it ideal as a base from which to explore Lisbon. In 5 minutes you can be at the river watching sunset. The apartment is close to many central transport links.
António and Mariana are kind, considerate and communicative hosts. Their recommendations are excellent. I particularly enjoyed regular Pasteis at Alfama Doce which is just round the corner.