We loved João and Monica's apartment. Located in central Alfama you feel just like a local staying there. João was a great host, very kind and generous and will provide you with as little or as much information as you need. His communication was good and he was waiting for us on arrival.
The apartment was spotless, quirky in a good way, and had very effective air-conditioning in the bedroom. The French balcony in the kitchen and full outside terrace is an added bonus.
Please be aware that in order to access the apartment you must climb an extremely steep set of stairs (not a problem for us though).
We loved Lisbon and would certainly recommend this apartment if you want to stay in Alfama.