Tiago's apartment is great! The location is really perfect, in the middle of everything and close to the subway as well.
It is located on a very busy street so keep in mind that it will get loud in the night, especially on the weekend (at least until 2 in the morning).
The best thing about this lovely apartment though is Tiago. Although we did not meet him in person (he had a friend of his waiting for us at our arrival) he replied to our e-mails incredibly quick and he gave us the best tips for our stay in Lissabon. Tiago knows so many awesome Restaurants and Bars/Cafès so that you don't have to worry about finding a good spot to eat. Furthermore he also provided us with insider tips on our journey throughout Portugal which we really appreciated. All in all: I would highly recommend this apartment!