Maria's place is great. We were a couple traveling with our teenage niece, and stayed in Maria's place while in Lisbon to visit the surrounding area. The place is located very conveniently, close to the tram in the downtown area where everyone wants to be, walking distance to many of the city highlights, and tons of restaurants. The views from the apartment are also great. The space itself was very nicely decorated, comfortable, and cozy. We enjoyed relaxing in the sofa next to the large windows to see the views.
Some additional information that might be useful: This is a good place to explore Lisbon using public transportation. We were doing a road trip and therefore had a car, and in this case, finding parking can be an issue in this area. This is not an issue with Maria's place, it is just the reality of staying in a popular location, so just to give those traveling with cars a heads up. There are some street parking options that are free after 7pm until 9am, and we used those.
All in all, if you are going to stay in Lisbon, I would highly recommend Maria's place.