We stayed at this apartment for 8 days to visit Lisbon & attend a conference at the Champalimaud centre, and it was everything that we wanted: comfortable, affordable, clean, ...
Thomas is very nice and helpful, and we met some very nice other people in the shared kitchen. Both the kitchen and the rooms were very clean and organized, and the free coffee was a nice extra in the mornings :). The location of the apartment is especially great when you want to attend something at the Champalimaud (10-15 minute walk), but it's a bit further from the city center. However, since it's very well-priced and Ubers in Lisbon are very cheap (5-8 euros to the city centre) that wasn't a problem at all.