Are you looking at current A4's or previous A4's (i.e. V8 or V6?)
IMHO previous A4's pretty nice, prefer it with a torquey engine and an auto. Only driven a 1.8T current A4.. was noisy. Otherwise pretty similar.
Gotta love Quattro, even in the dry
I'd probably take a C32 over a S4 V6 though.
good luck
Rusty