We have just returned from a 5 night stay at the apartments. We would definitely recommend staying at Sónia & Tiago's place if visiting Lisbon.
The location of the flat was great, within walking distance of main town and a lot of bars and restaurants including the market which we both loved! It is also near the trains to spend days at the beach if wanted.
The flat itself is was lovely and had everything you could need. It was clean and well equipped. A perfect size for 2