This is a great apartment, very close to all the sightseeing sites, and within walking distance of the Metro station.
Everything is new and very nicely decorated. We stayed there for 5 days and only once, on Friday, it was noisy from the street cafes. The only thing that I did not realize from the pictures, is that the bedroom does not have a window, however, it was not a problem for us and it was actually quiet there. Both - the bed and the sofa in the living room are very comfortable and both have very good mattresses. Fast internet. The communication was great, the check-in and check-out were smooth.
I would definitely recommend this apartment to anyone visiting Porto.