What is the difference between Audi A8's Quattro and Quattro Ultra AWD systems?

I am trying to decide between purchasing a new Audi A8 with the Quattro AWD system or the Quattro Ultra AWD system. Can someone explain the technical differences between the two and which one would be better for my driving style?

The Quattro AWD system uses a center differential to distribute power between the front and rear axles. The Quattro Ultra system uses a multi-plate clutch and an electromechanical actuator to disconnect the rear driveshaft when not needed, resulting in better fuel efficiency. If you live in an area with frequent inclement weather or like to drive in sportier modes, the Quattro system may be better for you. However, if you prioritize efficiency and don't often push your car to its limits, the Quattro Ultra system may be a more suitable choice.