We liked our stay at this flat. Tomás was really helpful and gave us a better map of a city and some tips for the restaurants. The welcoming book in the flat had also good tips on what to do and visit while in Porto.
The flat itself is quite small but it's a good place if you'rethinking of spending most of the time in the city.
I would recommend taking earplugs with you since the windows give way to quite a busy street. The location of the flat is excellent!