I rate this flat 10/10 and would definitely stay should I come to Lisbon again!
The flat is close to São Jorge Castle and a picturesque 15min walk down to the main square (alternatively take the public lift). There are so many restaurants and bars nearby, with a supermarket 10mins walk away. Despite being on a main walk for tourist, we had no problem with noise and felt very safe staying here.
The flat was clean and spacious, with all ammenities provided (fast wifi, crockery, cutlery, toaster, kettle, fridge/freezer, hairdryer, soap, tour book of Lisbon etc).
Tiago was there to meet us and give us a tour of the flat. He was a fantastic host and very quick to reply to any of our queries.
This flat made our trip to Lisbon much more worthwhile - I would highly recommend it.