We really liked our stay in the appartement of Manuela, Marta & Carolina.
The location is superb, near the Sao Bento station - but also on a walkable distance of a lot of sights to see, restaurants, bars... Very central for different things to see.
It was very clean, had al the necessary supplies. Comfortable bed and blankets. Enough pillows which I also like :) (I am always a tiny bit disappointed if you have 1 small pillow per person).
We would definitely come back here when revisiting Porto!