Its still an auto.
I was out in an A8 4.2 just a few weeks ago, and nice as it was, nothing gets round the horrible delay-lunge effect you get from the gearbox. You plant the boot, nothing happens, you wait, wait some more, then wham it finally takes off.
With a manual, the engine is mechanically connected to the wheels, theres no slush in the middle, and that completely changes the throttle response, and as a result it changes the confidence in the car. You see a gap and plant the boot to overtake something, you know that your going to get instantaneous response, instead of being sat on the wrong side of the road like a dead duck waiting for the torque converter to wind itself up.
They're suited to lazy cars with lazy drivers. Its not a performance transmission in any way, and that really detracts from an S model imo.