I drive my gf's E46 323i all the time and-
IMO audi interior is better and roomier up front,
-my audi is less tireing to drive,
-the steering is lighter but more solid (i dont know how that works but it does)
-i love the awd,
- i feel more confident in turns even with more body roll,
-much quieter at start and low revs and sounds better at high revs,
-it is not as touchy and the pedals are softer without being too mushy,
-better visability,
-mine has been absolutely great on reliability, ( i am **** about maintainence tho)
-the cars are pretty even in speed.. mine is has a bit more at the crank but losses more through the awd and her car is geared a lot tighter, her second gear is passed redline at 55 and mine redlines at almost 70 in 2nd

 

The first thing you'll notice, if you get a quattro, is the handling you'll be like "why have i been driving anything else?"
And I left a 2000 Type-R for a 2000 Audi I just love it drove in a m3 it was kool but I'd like the audi better.