The apartment is in the perfect spot of you want to visit Lisbon. Just next to Santa Apolonia train station and 10 minutes drive from the airport, in the outskirts of the Alfama district. Walk to Praca do Comercio is around 15 mins.
The apartment is as described and would perfectly fit a couple staying for a few nights.
If visiting during the month of June (saint Anthony's festival celebration in Alfama) the big plus is being close to the action w/o being annoyed by the crowd noises.
Paulo was extremely quick in responding to our messages and waited for us in the flat until late in the evening due to our flight schedule.
I Can only recommend others to stay at Paulo's place.