Unless you have tactile experience with Audi's AWD, I can't change your mind. I've owned 3 AWD Audi's (currently own 2) and can tell you without a doubt they are a marvel in wet weather and the snow. You can post all the tire rack vids you want but until you experience this system in bad weather you're clueless. I'm telling you that with regular tires it would smoke a RWD BMW on winter tires without a glance.
I do agree winter tires improve the performance of any car. But winter tires on an AWD Quattro would make a laughingstock of most anything else. Just watch those snow vids above. I can report the same experiences.