I stayed at this property for a week during my time in Porto. It is located in the residential area of the Boavista neighborhood, which is a great location. You are NOT right in the heart of the ultra busy areas of Ribiera and Baixa, but less than a half-hour walk away from all the major tourist sites. I also walked to the Parque and Museo de Serralves, which is about a one-hour walk away. Highly recommend visiting this museum as it was one of the highlights of my trip. Also highly recommend taking the metro + train down to the Praia do Senhor da Pedra, which is a gorgeous beach about an hour outside of the city.
The building is very quiet and well-equipped with WiFi, stove/oven, AC, washer, TV with cable, iron, hair dryer. The host is quite responsive with check-in details and recommendations for local restaurants and stores. It would have been nice if the kitchen was equipped with some basics, like oil and sugar, but there is a Pingo Docce grocery store, just a 5 minute walk away. There are also small wine stores, cafes and restaurants within walking distance.
The apartment is located on the third floor. There is a lift/elevator in the building, but it seems to break down quite often. It was thankfully working when I arrived, so I didn't have to carry my heavy luggage up to the third floor. But on my departure, it wasn't working. So I dragged my suitcase down the flights of steps.
The best part about the apartment is the spacious balcony where I sat outside to drink coffee and write in the mornings. Check-in and check-out were both very easy. Highly recommend this location if you want a more quiet spot that is still relatively close to all the major sites of Porto.