We enjoyed our stay. The apartment was clean, and in a great location which allowed us to walk everywhere. The only drawback is, the apartment is associated with the Art Stay Hotel - on the key card holder if reads when breakfast is served and to let the front desk know if we will be dining for breakfast. There is no mention of cost which made us think that this breakfast was a complimentary / continental style breakfast, when in fact it ended up costing 40€ per couple for the 2 mornings we were there. I think this is important to mention because there are many other cheaper options for a quick and easy breakfast instead of eating the breakfast offered. If you want their breakfast just know there is a cost associated.
Otherwise we really enjoyed the apartment, it’s quiet on a very busy little street, and a great oasis from the hustle and bustle of touring around Lisbon!