My wife and I spent 3 days in Lisbon at Goncalo's place, and we enjoyed our stay. The apartment is located in a great safe area, and it is charming and clean. Goncalo made us feel welcomed by meeting us when we arrived. The communication was also excellent! We walked everywhere the first day, including the Market, restaurants, coffee shops, Museums, etc. The apartment is also conveniently located near public transportation and, we took advantage of public transportation to get to places that we wanted to visit in Lisbon and to go to Sintra.
I would certainly recommend staying with Goncalo.