Maria's solution is in the perfect location, close to a really big bus stop (Praça da Figueira) and a couple of Metro stops (Rossio and Martim Moniz), even though it's such a central position we almost always walked everywhere.
It's truly in the heart of the city, close to a lot of bars, restaurants and shops
Maria and Miguel are wonderful hosts, very communicative and helpful, the apartment is filled with utilities to satisfy each needs including a small kitchen we didn't end up using since we wanted to dive in the wonderful Portuguese cuisine (and I'm glad we did!)
Hope to visit Lisbon again soon, thank you (: