We had a good time in David's apartment. It's small but everything is at it's place and we could easily squeeze in with 5 persons!! The location is very central close to the Barrio Alto and just minutes away from the Old Town. It's also in a very quiet street, we could sleep without problems. We hadn't any problems to reach David or his friend on the phone and they helped us to find the place and showed us around.
Lisbon is a great place to visit and we're stunned by the beauty of this city! But be aware of pickpocketing! They got me :-(