We had a great stay at Helena's place. It is right beside the Estrela Park so we were able to go for a run every morning before heading our for the day. Although it is close to public transport we walked to most places (apart from Belem - not to be missed - and the Aquarium, which are both on the outskirts of the city). It is close to the Mercado de Campo, which is a more local/intimate version of the Time Out Market and Principie Real, with some excellent restaurants including A Cevicheria. As advertised, Helena always responded to requests within the hour. Would highly recommend.