The E63 AMG S loses from a stop and from a roll. It does get the lead from a dead stop as it should by virtue of all wheel drive but the M5 closes the very quickly. It does not seem to launch, just roll into the throttle.
From a roll, the race goes to the M5. Now, the M5 should have the advantage from a roll thanks to the dual clutch transmission and rear wheel drive setup. All wheel drive also does have higher drivetrain losses but that is one of the reasons AMG gave the car a power boost.
Is the M5 modded? Are both cars stock? Who really knows with a video like this but the result sure is interested. Check out the video below.