Performance vs. Standard RS6 Actual Differences?

[alexrs6plus]

Don't forget the sports exhaust, tinted rear windows and a choice of the optics pack colours except carbon for free.

Also lower emissions (Audi claim) so fell in a lower tax bracket.

[MikeFish]

And as the optics pack were already included the carbon pack was cheaper.
But the original question was about mechanical differences between the 2. Plenty to threads here discussing the other changes.

[alexrs6plus]

Sorry, I got lost in all the posts