1. Message communication was smooth and friendly from reservation to check-in.
2. Easily get to the apartment at once from the airport by metro (about 30min), and convenient to use a bus or metro to go out.
3. Clean and pretty accommodation with good kitchen and bathroom(shower booth only) facilities like own home. (but, no washing machine and change towels only once every 3rd day.)
4. Across the street from the cathedral, there was a large FROIZ supermarket for a comfortable meal.
*Thanks to InSitu, I'd enjoyed a comfortable stay in Porto.