Let me first say that Paula was an amazing, helpful and kind host. Her house is beautiful, full of life and well arranged flowers. You have everything you would need!
This said, the room we had to stay into was extremely noisy (we are very often travellers and have been sleeping in different situations - from hammocks in national parks to dorms with 12+ beds) and this was the firs time (even with earplugs) that we could not sleep. It says "maybe some noises" but you should definitely avoid the room during the weekends.
It is right over the street and during the night you have an orchestra of drunks and speeding cars. Again - the flat is beautiful, but we did not go to Porto to stay in the flat - we paid to sleep, which did not happen during 3 of the 4 nights we were there.