In short: The apartment is absolutely lovely and perfectly located in Lisbon and Anasus has been the best host you could imagine. Very friendly, helpful and cordial, with great tipps on what to do in Lisbon. Everything is superclean and just as presented here. It's on a street of Barrio Alto that is mostly very quiet. You will have party-goers walking through that street at night here and there but it never affected me. One thing to consider: As mentioned in the presentation of the apartment, the Wifi is not super strong. If you're dependent on strong Wifi in your apartment, take that into account. For me it was no problem at all.
Again, I couldn't have asked for a better stay. Muito obrigado!