Daniela was busy when we arrived, so her lovely friend Birgit met us where the taxi had dropped us off, walked us to the apartment and showed us how everything worked. Communication with Daniela was extremely easy and friendly at all times. The apartment was exactly as described, in a wonderful location right in the middle of the medieval part of the city with lots of fado restaurants and ginjinha bars nearby. Daniela's recommendations for restaurants etc were spot-on too.
The only minor irritation was that we were overcharged by the taxi from the airport. Birgit explained to us that in Lisbon the taxi-meters are sometimes hidden (e.g in the glove compartment) so you must demand that the driver display their meter when you get in (we looked into lots of taxis while waiting for ours at the airport and none of them had a meter that we could see). When we return to Lisbon we'll remember this tip!