We booked the tour with João (out of 5 offers of which all of the others were cheaper) because of his promise to walk us off the main tourist routes. And he kept word.
We had a great 5 hour walking tour through Lisboa starting at our hotel and probably covering all the important places, where we met other tourists and a lot of the "unimportant places" where we hardly saw others.
João has a deep knowledge of the Citys past and history and explained whatever we asked him.
We can only recommend a tour with João!!