The apartment is much bigger than it seems in the pictures and very well located. It has been done up tastefully and is a relaxing place to come back to after a day of walking around or night of partying in Lisbon. The central location makes it within walking distance to many of the key landmarks in the city. The Time Out market and many bars and restaurants are a block or two from the building.
One point to note is that the apartment is located on the 3rd floor of a building without an elevator. So older folks would need to consider that, especially if they have heavy luggage.
Overall, Sofia's apartment is a great place to be based in to spend a few days in Lisbon.