Elsa's place is exactly what you need in Porto. It's well located in the heart of the city, but in a quiet area where you're not kept awake by noise. Tons of restaurants, cafes, pharmacies, supermarkets, etc close by. It also has parking in a garage nicer than most houses (think James Bond's garage) so you don't have to worry about your car.
The house is very modern with a great aesthetic and one of the best showers I've had at any airbnb / hotel ever. We arrived on Christmas Day and since most of Portugal is closed Elsa bought us some food beforehand so we could have something to eat. She was the best host! We loved it so much that when we are returning to Porto we booked it again. Check in / out is a breeze with lockbox, garage remote, keys, etc all available so you don't need wifi to contact the host.