Very happy with our trip with GuestReady. It was clean, comfortable, fairly well equipped and has an enjoyable balcony. There is also a comfortable bed in the upstairs room (the downstairs beds are smallish single beds that my travelling companion pushed together - she had no complaints about the sleep!)
The apartment in close to town (20 minute walk) so is a good place to access the rest of Porto from if you’re not looking to be right in the heart of the city, but be aware that the location is close to the train tracks and is in not a beautiful location (the balcony is nice to have but don’t expect a view to write home about). If you want to bowl someone off their feet with a romantic retreat, this probably isn’t the place to do it. However, if - like me - you’re looking for a base to work or a base to keep your belongings, have a good sleep, and cook some dinners, I would recommend this place.