The do it all super car
I have been searching for five years to find the ultimate combination of performance, practicality, luxury, and understated styling. This car has and does it all. While the RS6 beets this hands down, this car has more than enough oomph and rail-like handling to make me smile from ear to ear. Beside, have you tried stuffing a few kids and a few dogs with associated gear into your uber-sedan for a treck acroos the country? Also, exactly where do you live that the roads and the cops will let you test the limits of your double turbo Porsche?
This car is wonderful.
Recently purchased this car Audi CPO. Drove it 1000 mi home - It was like a vacation. This car is perfect. Everything from the dashboard lights to the advanced braking system work in perfect harmony. Some notes: leather seats without alcantara insets are simply TOO slippery for spirited driving. I spent a lot of my trip home planted to the door because I slipped out of my seat. (Learned to offset that a little by stomping on the dead pedal.) Probably wouldn't be an issue for a wider person. Yes, you get terrible mileage. It IS worth it. If you're doing mostly highway miles (like me), you're getting about 18 mpg, which isn't horrible. City? Hopefully you don't drive very many miles :)
Family Values
If you have children and passion for what you drive, this is the car for you. Those who cannot or will not work on your own vehicle, move along. Audi cars do require extra service attention, but the 2002 S6 Avant will reward you handsomely with luxury, performance, style, and comfort that no SUV or mini-van can or will.
Stealth Wagon
I agree with the others here; this is a sports car that just so happens to be in the form-factor of a station wagon. It is extremely difficult to observe posted speed limits. Use the cruise control or you'll be sorry (only took me 2 weeks to get a ticket from a country bumpkin speed trap dude). I can not even fathom what the RS6 will be like. 450 hp? They must REALLY haul on the autobaun.
Just Awesome
Picked up my S6 as a CPO car after lusting after one for years. I previously owned a 2000 A6 sedan, and the S6 is everything I wish that car had been. This is simply the best wagon ever: gorgeous, fast, luxurious, and incredibly useful. The fuel mileage is abysmal, but I was fully awared of that going in, so it's not really a negative point for me.