I've stayed in quiet a few AirBnBs and, though my experiences have always been pleasant, this place topped them all by far.
The flat is in the heart of Lisbon and walking distance to both the Cascais (Cais Sodre) and Sintra (Rossio) train lines. There are loads of shops, restaurants, coffee shops and bars practically on your doorstep and, miraculously, no noise in the actual flat.
The flat is super comfortable (borderline luxurious) and has been carefully prepared with everything you could possibly need. The guys who run the flat are super approachable, helpful and professional and stock the flat with loads of thoughtful little touches like a list facilities in the area, a bottle of wine, chocolates on the bedside table ...
A truly great place. I can't recommend it enough.