The apartment is very central and very easy to find (My friend and I arrived via Uber from the airport) and also very walkable, close to good bakeries and a big market. Check-in and check-out was easy, and Pedro even let me borrow some plug adapters after I forgot mine.
Since you are so central, there will be noise at night on the weekends (Fri/Sat) from typical revelers in the street and the recycle bin nearby, but you can close the windows and turn on the air conditioning, so it is just regular city background noise -- I had no trouble sleeping. Sun- Thurs is very quiet. The neighborhood is lively and also very safe. My friend and I (both women) felt comfortable walking around the neighborhood late into the evening / early morning.
The apartment has all the things you need to mix it up between restaurants and dining in (making coffee, enjoying a glass of wine and goodies from the market) so it makes for a relaxing stay. If you're new to Porto like we were, this is an excellent apartment to choose.