Hi I currently drive an a6 black edition, my dealer is obviously looking to make up no's I have been offered a new a6 black ed for 20 pound less than I pay now or an a7 sline for 26 pound more. Question is am I better off with an A6 black ed or the A7 sline I like both but can't decide. Is the drive of a multi and the a7 much better, worth losing the privacy glass and titanium rotors for?