We stayed in 7 different places over two weeks in Portugal, and this was by far the best.
The building was obviously newly renovated, and everything in the apartment was built with thought and quality. My girlfriend is an architect, and even she was impressed with how nice this apartment is.
In terms of amenities, you get everything you need, including life-saving AC. Location is central enough - 7-10 minutes walking from the metro which goes to the airport. The WiFi was the fastest we had throughout the trip.
Pedro was extraordinarily helpful and welcoming, and helped us with everything we needed.
If you are in Porto and this apartment is available, I sincerely recommend you look no further, it is an incredible value for money and a great place to stay.