Daniel's place is indeed a great point to start discovering Porto. It's really well located, yet, not in a noisy hood. In 5 min or less, walking, you are in the very centre of the city. Also, there is a market and some local bars more authentic that other typical ones. Apartment has all you need (well equiped kitchen with oil, plenty hot water in the shower, really comfy bed..). And spotless, one of the cleanest airbnb I have ever been