I have spent 2 months in this apartment and I have enjoyed it a lot. It offers a great view over the Tejo river and in mornings the sun will wake you up. It is quiet and still very central in Alfama, not far from the Metro and other public transport. If you don't mind walking a bit through the town, it's a good place to stay.
The best part of it is that it is located on a high flor, so you can enjoy a good view and feel safe. Also as soon as you enter this district of town, the busy streets of Baixa Chiado or other Business areas are left behind you and you enjoy the charming little streets of Alfama, one of the oldest parts of Lisboa!
It might be a bit small for two people, depending how you long you stay. Unfortunately it doesn't have a balcony, but in the nearby park you can always enjoy the sun!
The host, Isabelle and Cesar were very helpful before and also during my stay.
I would recommend this place again. Thank you!