I just found this review online which was written by cars.com this month. It didnt have too much nice things to say about the 2009 A6 V6. The editor complain about drive by wire lag as much as a full second, a touchy brake pedal, low quality buttons, ***** and stalks and the lack of room in the front and the back seats.
Personally, I have never felt any lag in my A6, but I have a 08 without the supercharge. My brakes are great and have just the right feel. I am not sure how big the editor is, but I have plenty of room no matter where I sit in the A6.

http://www.cars.com/go/crp/research....ection=reviews