Aida's apartment is very beautiful and comfortable, rooms are really nice and the terrace is relaxing (there's also a hammock!) and perfect to admire Porto's blue sky. Aida and her son have been very kind and useful: they are open to help with any problem and ready to fix it.
The house is quite close to a metro station and a 25 minute walk from the river and downtown. If you visit Porto during winter be prepared with warm clothes! The house is very big and needs some time before the heating system kicks in!
I would definitely suggest Aida's place!