Great location for up to six people. You can walk all of Lisbon from the apartment (except the Belem tower, but that one is far from the city anyhow) and are very close to done of the most beautiful viewspots in town - we enjoyed sunrises and sunsets basically every day :)
The check in was very smooth and Gabriela is a fantastic host and gave us some great recommendations for food and activities so we could really make the most out of our stay. The apartment is also much bigger than it appears on the pictures, so don't be afraid booking it :)