Our family of 7 (two grandparents in their late 60s, myself and my husband in our 30s, and three kids ages 9, 5, and 2) had a wonderful stay in this apartment! The first thing to note was the amazing service - our plane from the states to Paris was so delayed that we missed our connecting flight to Lisbon and we were almost a full day later than we said we would be. The communication was excellent, and our host was there to meet us when we got finally arrived.
We got a thorough tour, and there is a binder of information about local restaurants, activities, etc. There was also a manual on every appliance in the apartment. There was coffee and some kitchen staples provided, and we had all the necessary items (pots, pans, dishes, etc) to make dinner for 7 for many of the nights we were there.
We found the location to be perfect; it is a very vibrant area, and the kids - and adults! - loved having the windows open and watching everything going on in the square below (not to mention taking in the beautiful view). It got to be fairly loud as the evenings went on, but the windows are a miracle! We could not get over how the apartment became silent when the windows were closed. So we got to be in a lively area, and still experience complete quiet when we were ready to go to bed. We walked to many parts of the city from the apartment, and found it to be very convenient. It was so nice to have the Time Out market so close by, and we ate there several times during our stay. Any time we chose to take a cab (for instance, after a long day in the Belem area), it was extremely cheap. One of the conveniences we most appreciated was the Minipreco just steps away from the apartment. We got everything we needed there including breakfast pastries, milk, anything we needed for dinner (good variety of fruits and vegetables), wine/beer, and even diapers for our littlest traveler. We were there every day and were so grateful it was right next door!
All of the appliances worked well, including the air conditioners which were life savers while we were there!
I truly think this would be a good home base for almost anyone visiting Lisbon. The only exception would be anyone who would have trouble with the stairs up to the apartment. It is on the 3rd floor (4th to those of us from the US), and they are pretty steep. Our group did fine, but anyone with mobility or health issues might have a problem.
Overall, I can't rate this apartment highly enough - we loved our stay here!!