Saving those 350lbs goes a long long way.
That and a significantly better chassis. Remember, this is now a BIGGER car!
Was there any testing on a race track with plenty of corners? The new vehicle, unless I'm reading that wrong, appears to have better grip, so that means in theory it should be able to go into and through corners at higher speed which would negate the advantages of the larger engine.
If it corners faster, that means higher exit speeds while keeping the power of the strong engine to punch out of the corner. Those are all bonuses.
also, i recall seeing a spec of the braking being something like 96 feet (don't quote me the exact number, but it was lower than listed upthread)...maybe that model had the upgrarded Brembo brakes (i don't know if that is a trim/option)...the reviewer said it was the shortest stopping distance of any sedan ever tested.