The apartment is well positioned, between the airport and the city centre, in easy reach by subway of both, and with a lovely park close by. There's a pharmacy next door and several supermarkets nearby. A negative side of the location is the rather loud street noise, so if you're used to sleeping in a more quiet environment, bring earplugs.
We were there in February and I must say the stone floors were rather chilly (though the apartment does have several fan heaters), but that is probably an advantage in summer heat. Other than the cold, the rooms were as promised, the beds comfortable and the kitchen well equipped. We loved the table football!
The hosts were very helpful and quick in responding to our issues. The tips offered for what to do in Lisbon were great and we made use of them along with the map provided. The city is gorgeous and we are very happy with our trip!