This apartment is a beautiful and very large luxury space that comfortably fits 6+ adults. Located in an excellent part of town you can walk to many of the top sights.
It is also down the block from a grocery store and only about 5 minutes from a metro station.
The space is a professional rental, meaning it does not have the homey touches of staying with a friend or a traditional B&B, there's no breakfast included and only the basics are provided (TP, towels, hand soap, bed linens, and wifi).
If you're aware of that from the outset, it can be an excellent choice for visiting Lisbon.