I have had the 2.0 Quattro for just over a year now. The ice storm here in Atlanta gave me my first good chance to try out the Quattro system. I was really impressed with the combo of Quattro and ESP. It actualy took some of the "fun" out of driving...
There are a couple of glazed over hills in the neighborhood that have denied a ton of cars but the audi walked right up. I even turned ESP off and juiced it pretty good and although spinning a bit, I moved along pretty easily.
Today we will be taking out the RWD C300 and see how she fares...

 

Just an update...my C300 sucks in the snow and ice...comparitivly speaking anyhow. Although popping the clutch in a rear drive car can be a bit more fun...away from traffice, light poles and cars...
Long live Quattro!! Does anyone have any comparison views between Quattor and other manufacturers systems?

 

Unfortunately I can’t offer a true comparison, since I don't own an Audi yet. But I can offer you my views on the Subaru version of AWD.

I've owned a 02 WRX Sport Wagon, and currently own a 04 WRX STi. I got to drive the Sport Wagon in Delaware during the winter, and I just moved to Georgia after 3 years in Alaska with the STi.

Both cars handle extremely well in the ice and snow. Never had any problems starting from a stop (both cars are manual) or turning. Unfortunately I have the problem stopping that everyone else does. Though a good snow tire will help tremendously. Ran Blizzaks on the STi.

Though Subaru has a front wheel bias with their AWD setup VS Audi with a rear bias. As long as I wasn't doing anything stupid (speeding, or whipping into turns), I didn't have any problems. I'd occasionally feel the car slide, of feel a loss of traction, but never had the feeling of loss of control. I'm hoping to get the same from my Audi when I get one.

From all the research that I've done, and a little personal opinion on my part, I feel that Subaru and Audi have the best AWD systems out there.