I know they also retuned the suspension and such, but it still suffers from all of the problems of the normal A8; such as numb steering, poor weight distribution and poor power split from front to rear.
There is nothing that can compete (with a stick shift) with the driving feel of the BMW 7-series at that size and price point, so I would take the 750 in a heartbeat. And Lexus? The car they have in this class is the LS430, which is indeed a potentially sporty car which is murdered by it's safety nannies and compliant suspension.