Lovely apartment in the greatest location possible- five minutes walk from the metro, bus and tram stations that take you to all the places you wanna get to around the city.
The host was superb, polite and welcoming ,and the check in and out process was easy.
We were three adults but the flat was with enogh space for even 5 (2 king size beds + 1 camp bed, all were comfortable).
The one thing I liked the most was the neighborhood - Baixa is pretty much the only one which is flat, and that will save you A LOT of walking in sharp ups and downs in the other areas such as Bairro Alto and Alfma.
Will certainly stay at this place again if I ever visit Lisbon once more, and I recommend you to do the same :)