I recommend Dixo'S's place for a stay in Porto.
The communication with the host was quick easy and very effective. Ines and Pedro were helpful and solved everything I needed.
The location in Porto is excellent, near the riverside and walking distance to the most beautiful areas of the old city. It's also well communicated by metro, bus, tram and train from other valuable areas of the city and the country.
The apartment is spacious, pleasant and well decorated,
Although i's a pleasant space to stay, if you are planning to spend long time inside the apartment, take in consideration that the daylight is limited and the presence of the neighbours of the front facade near and very discrete (as usual in the majority of streets from Downtown Porto).