Wow, this thread moved a bit since my previous post!
Ok so my current A4 is the only car I have ever owned that applies the brakes if it picks up that coasting alone won't slow you down enough in the appropriate time, I tested it again yesterday and it does apply the brakes, you can feel the difference between coasting (with instantaneous consumption showing 0l/100km) to the brakes being applied. There is however no internal indication that this is happening, I'm sure the brake lights must also illuminate otherwise it would be down right dangerous, and the CC remains engaged. I'm guessing it would be useful in areas where the posted limit changes regularly.
On a side note, DSG is the VAG group's double clutch transmission, it has 1st,3rd and 5th on one shaft and 2nd, 4th and 6th on the second shaft (shaft 1 is inside shaft 2 which is hollow) each shaft is connected to a separate clutch. This allows for very fast and seamless shifts as both 1st and 2nd can be engaged at the same time, as the clutch on 1st is being disengaged the clutch on 2nd is being engaged allowing for near instantaneous shifts.
Regarding the long journey, it was a bit taxing for sure, but we took it easy and stopped for nice breaks ever so often (having a toddler and a pregnant wife in the car ensures the stretches can never be too long!
) I used to do onsite work (call outs to customers, some of which were rather far afield) so I'm rather used to long drives.