I think if you look at the sales, at least US figures, Audi is far behind almost everyone else. 2009 Top Luxury US car sales:
1. Lexus 215,975
2. BMW 196,502
3. Mercedes 190,604
4. Cadillac 109,092
5. Acura 105,723
6. Audi 82,716
As you can see, at least in the US, Audi is 6th place in total sales. Those Audi commercials need to be "strong" and "edgy" in order to get more peoples attention and increase their sales.
That being said, I think if I was in the market for a new car, it would probably be a new Audi A4 Avant Wagon. I'm not a fan of the current crop of BMWs, except maybe the E92 series.