Summary: Unsafe location, would not recommend.
Did not have a very good experience here. Main issue is there are tons of homeless people doing hard drugs day and night right next to the apartment. We didn't feel safe walking and always felt we had to order an Uber. The apartment is also up one of the steepest hills in Porto - it is like a 45 degree angle walk up from Sao Bento station nearby so you can imagine how fun that is to carry luggage up.
Check in process was a mess - you cannot access the wifi from the street so you cannot use the app to open the door. We had to pay to use cellular data as it started raining as we were fumbling to get the app to work. There is a lock box on the wall outside that the owners confirmed is theirs...not sure why they don't just put the key in there.
The apartment itself is clean and nice but those are the only nice things I can say about this place. The water gets scalding hot in seconds so it felt super dangerous trying to take a shower because it would randomly get really hot.
Overall this place felt unsafe and the communication with the host was not the best (late responses or automated responses). Would not recommend this place.