Our stay at Sandra and Joana's place was nice. It was a bit smaller than we anticipated, but that is just the difference between European and American home sizes. The two best things about the apartment are 1) It is in a perfect location for seeing Lisbon. Located in a quaint historic location, it was easy to get anywhere we wanted. The metro is only about a 5 minute walk away, the train is only 10 minutes away, and there are multiple bus stops nearby as well.
2) Joana!! She was fabulous. We had an issue with one of the beds, but she fixed the problem in just a few hours. We needed some adapters for plugging in our phones. She had them for us in about 10 minutes. She was FABULOUS. She was extremely responsive, kind, and helpful.
There are two things to be aware of and these are primarily for families with kids. 1) The hot water heater is small. We are a family of five and two of us could take quick showers before we had to wait a couple of hours for the hot water heater to refill.
2) There was lots of noise from upstairs. It wasn't party noise. You could just hear a lot of walking and moving things around, and a lot of it took place during the night. So if a family has kids they might want to be aware of it.
Overall, we would recommend Joana's place. Again, great location and excellent host!