We had a lovely stay in the apartment. Most of all, we were thrilled by its location, in Alfama, a neighbourhood with such a vibrant atmosphere, so close to stunning viewpoints, Se de Lisboa, Castelo de S. Jorge, Santa Apolonia train station, Graca neighbourhood, etc. Despite being in the centre of Alfama, it's not too noisy and we didn't have problems to sleep. We also loved the blend between the local people and the tourists. Our neighbours were locals and really nice people.
The apartment was in good condition and we didn't feel it was too small as every room is separated, so it isn't really a studio flat but more like a small apartment.
It is really bright and airy because it has windows in every room, so it was never too hot even though we visited in summer.
The only thing I would point out is that the sofa is tiny and old, and the electric cooker is also old and takes a while to cook. However, these minor details weren't a big problem. We adapted and also enjoyed having TV and WiFi. The host also provided washing-up liquid, detergent for washing clothes, toilet paper, and there was oil, salt and coffee in the kitchen.