G-Rig, yes it's noticeably more smooth in comfort. And if I go round a bend at speed in comfort mode I instantly notice far more cabin lean.
It's such a decent difference I always change the settings on the fly depending on what the road is like within a ten minute drive to work.
Whitejames - I'm pretty sure the ACC doesn't adapt to the road type itself.
This would be impressive though. As I have ACC, I can tell you it's definitely not a gimmick. I think it's the best thing you can add to the Mk6 as when you couple it with sport vs drive on a DSG, you can essentially own two cars in one.