We did not recommend this place for the reasons mentioned below :
1 - before your arrival, you are asked to check in online and if you want to receive the keys in front of the apartment, you have to pay an extra fee of €10, which is not acceptable given that this information is not mentioned before when you book the reservation ;
2 - if you do not want to pay €10, you have to go to a place in town to receive the keys. We indicated that we will be there at 2:00 PM, when we arrived, nobody was there, we waited (with at least others 15 persons in the same situation) for almost 45 minutes. This is not a professional conduct, specially for an agency ;
3 - then, when we finally arrived at our place, the key didn’t work well and we spent 20 minutes, trying to open the door and to reach the agency to have a solution (during our stay, we lost 5 minutes each time to open and close the door). I hope you are not in a hurry when going somewhere ;
4 - the bathroom was clean but not the surfaces. The room was dusty, the pillow case was ripped, the door handle of the bathroom was not well fixed, there was a coffee machine but without its tank, thus impossible to use ;
5 - when you leave, you are asked to pack bed linens and towels and to take your garbage and throw it outside by yourself. We didn’t understand why you have to pay cleaning charges regarding the fact that the room was not clean enough and that you have to do part of the job when leaving ; and
6 - last, we did have communication problems. The person who was in charge of the Airbnb chat was very responsive and trying to help but that was not the case of the other members of staff of GuestHouse.
Good points were very rare : it is well located (but very noisy, noise from the street and the other guests inside e.i. door slams, bring your earplugs) , the terrace and the (very little) kitchenette were ok.
There is a lot of nicer place in Porto and people are very kind, if you have the opportunity to chose, pick someone who is caring about their guests and not GuestHouse.