Joao's place is amazing, extremely cozy, clean and comfortable and as soon as you pass the threshold it gives you the feeling of "at home". It has everything you need for a relaxing and enjoyable holiday and also it's very close to all touristic places, restaurants, supermarkets, Ribeira and the pedestrian bridge which connect Porto with Gaia.
Joao is a wonderful host, very helpful and friendly and all his recommendations were more than useful and interesting.
For now on, there is no other option for staying in Porto than Joao's place.