My friends and I stayed at Óporto.INguest for four days, and we had a fantastic time! The home is very well-decorated, comfortable, and spotlessly clean. It also has an amazing view of the city from the kitchen. The house is not directly in the center, but it's very easy to get around with the buses and metro.
Antonio is an exceptional host - he really went above and beyond our expectations. He greeted us with breakfast upon our arrival, and even printed out a boarding pass for us late one night. He visited the house every day to check on us and make sure everything was okay.
If you're staying in Porto, there's no better deal!!