I owned a B5 (00) S4 biturbo, and have a C5 S6 avant right now. Very solid cars, albeit nose-heavy.
Reliable, albeit high maint (off warranty find a good indie!)
The newest Audi S-cars apparently have several significant improvements over my generation -
1. smaller, forced induction motors result in good economy
2. New diff config allows the motor to be moved back 6" - audis are/were very nose-heavy ("911 in reverse")
3. Torque vectoring diff, if you got it
4. supposedly improved QC/reliability. Honestly, mine have been OK. But i maintain and treat them well
I like my 11 year old S6 enough that i'm putting significant t$$ and effort into making it "better than new" including replacing the old struts (ok, they're not struts,tell me what to call them) and a broken spring with KW coil-overs, set to their highest and softest setting :-) Excellent reviews as a road suspension.
Don't fall for the fallacy that AWD makes snow tires obsolete. Get a set of smaller diameter, narrower wheels and mount 4 Dunlop Wintersport M3s on them. You'll love it in the winter. As it is, AWD let's you get up a head of steam to arc gracefully off that cliff!
Grant
Grant
gee-lenahan-at-gee-mail-dot-com