The apartment is great, we really enjoyed our stay there as it's located in an area that's close to all the main attractions as well as restaurants and bars. Porto is quite small and walkable, and it was great to come to and from the apartment when sight-seeing.
The apartment is located on top of one of the best Tapas bar in Porto, however, they have live music that goes on until 1 or 2 am and this includes Sundays, which made the flat extremely noisy as it faces the patio where the music is played.
Other than the above, the flat is clean, the hosts are friendly and for a short stay you can't go wrong.