Fantastic apartment - clean, ultra modern, airy with all the modern appliances available. Very close to the central district with restaurants and nightlife as well as starting point of most touristic tours.
Some flips, just so you know: This is part of a group of serviced apartments, not a stand alone apartment. While towels etc are provided, consumables like shower gel, shampoo aren't.
Don't be too enamored by the balcony, apart from the occasional peek you won't get much value off it. The building is a heritage building and the elevator is slightly scary!
That said, none of these are deal breakers. The apartment overall is a great value for money.. they add other nice touches like a gratis pocket wifi device (for those who don't have a net connection).
Overall, if I came to Lisbon again, I wouldn't hesitate in booking the same apartment.
Highly recommend.