The apartment has everything you will need for your stay in Lisbon. The space is very comfortable, with a light-filled living room, a kitchen if you want to cook at home, plenty of room in the bedroom, and a nice, clean bathroom. (I was traveling alone, but the apartment would be perfect for a couple, as well.) The view from the apartment over the orchards and vinyards of the Instituto Superior de Agronomia is very pleasant, and the view of the 25th of April bridge and the Tejo from the patio on top of the building is wonderful. I enjoyed several sunsets on the patio with a glass of beer during my visit.
It's a short walk to the the Calvário center or the LX Factory for a nice selection of restaurants. For eating in, there are several places nearby to buy groceries, ranging from small shops to supermarkets. There aren't a lot of tourist attractions in the immediate vicinity of the apartment, but there are many good public transportation options (buses and trams) to get you efficiently and cheaply to the rest of the city. And, of course, taxis are relatively cheap in Lisbon.
João Tomás and Joana are friendly and responsive hosts. If you need anything, they are quick to respond. I was very pleasantly surprised when I arrived to find a nice bottle of wine, some bread, and some fruit.