What parts are the same and can be interchanged?

[MAtkisson]

What is the real difference between those hubs?

The difference is hubs is the offset.

[_ShurikeN]

Mystifying

Are there any known details?

[Vorsprung durch Technik]

My 2.8 rear hubs aren't of yet but will be soon and will be interesting to see the difference to my S6.Also i thought the Bearing size was bigger on S6?

[_ShurikeN]

No, the bearings are the same, both are 82mm. S-hub has smaller offset than non-s one. Presumably about 4mm smaller.

[priba]

upper part on the rear shocks are different between S and standard quattro
no rear ARB on standard quattro

rear bearing housing is different for S type 'cause of ARB
there's no difference in track width between quattro and S, as far as I know