The plane is bigger, faster, smarter, and more economically and enviromentally efficient than the 747.
It would be used on long-haul flights, like from New York to Tokyo.
Each system has several coutnermeasure and failsafe systems to back it up, so there's very little chance of the flight being delayed because of mecahnical failure. Not only that, but each system has sensors that tell when it's going to fail, so that it can be serviced beforehand.
The craft has two full passenger decks (the 747 has basically one and a third), which allows it to carry somewhere around 600-800 people. The engines are state of the art, and provide an astounding fuel efficiency rate.