Just to share my own experience. I have 19" rims with mag ride and I find that the tire pressure plays a big part in affecting the comfort level.
I followed the Audi recommended tire pressure of 42 and 39 psi for front and rear tires respectively and find that they are too firm.
Read from other forums and found that other owners seems to be happy with around 39-40 for front and 3 psi lower for the rear.
I tried them out and settled with 39 front and 36 rear for my S3 sedan.
ps: I am not on lowering springs yet... will see how that affects the ride when they are here next week.