I stayed for a week and all was great. Location is perfect as it's very close to the centre of Porto (15 minute walk) very convenient if you have a car, as they have a parking spot allocated for you in the building and it's not too deep into the centre of the city, so you can manage to avoid the heavy traffic one can usually find in Porto after working hours.
Check in was very smooth and didn't have any problem at all. Quite spacious flat with all amenities one may need for a stay.