Loved our recent stay in Lisbon and would absolutely rebook at this, or one of their other air bnb properties as they have several. The space was perfect and the hosts were extremely engaged/helpful. They even had a little welcome basket when we arrived with wine and sardines, which really started the trip on the right foot. The neighborhood is extremely walkable - we never had to get in a taxi once. Highly recommend.
The only thing I'll mention is the flat is right above two very noisy bars. It's a very charming street with several restaurants and a great coffee shop as well. The closer to the weekend it got the louder it got. If you are a light sleeper or don't live in a city where you are used to noise I'd suggest ear plugs. That would easily fix the situation. I live in a city and it was noticeable but I was fine. My travel guests live somewhere very quiet and struggled a bit to sleep. But ear plugs would easily fix that.