I was the first guest ever. Everything in there is new and functioning. If I can think of any downsides, I'd say one is that the bedroom window opens to the corridor, so a bit difficult for fresh air to come in, and another is that you can hear when the guests from the other apartments walk. But then again I slept well and undisturbed.
From the terrace you can see something impressive - in all her glory, the cast figure of Nossa Senhora do Terço e Caridade is looking over you.
The location is great, very central but not noisy. You can cover all of downtown Porto and also one day hop on bus 500 to get to Matosinhos (i.e. to the ocean) and then walk further north to Leca de Palmeira to enjoy the beautiful beaches. Have a nice time!