vdubturbo. nice review. Having owned the C7 A6 for almost a year, I can certainly agree with most of review.
As far as the exterior styling, I have to give it to the F10, the A6's lines are simply not as eye catching. The A6's center gauges and center info center are among the best I have ever seen, I actually like it better than BMW's wide screen because I dont need to take my eyes off the road. All your MPG, digital speedo, navi info and efficiency infos are on the center info center.
You forgot to mention the seats, the multi contour seats are one of the reason I switch from the A6 to the F10, big difference in comfort. The width of the 2 cars are about the same, the F10 do feel wider and more comfortable for some reason. The volume knob placement next to the shifter made sense to me because the presents are down there as well. I like the HVAC better in the Audi because the AC was colder and I dont have to play with the temp know and that silly hot and cold mixer knob.
I find Audi's 3.0T engine to be quicker than the N55 by quite a bit. The A6 just feels lighter and more agile. Handling wise, I thought the A6 handled better in the corners, but then I do not the sport package on both cars. The F10 definitely feels more stable at high speed and the steering also feels better at high speed, the F10 is also quieter on the highway. My A6 had a few minor rattles, the F10 just feels much more solid. I have the BMW premium audio as well, dollar for dollar, the B&O system doesnt even come close. I think the B&O is a bit better, but certain not worth seven times the price.
In the end I agree with you, both fantastics cars, but I like my F10 better.