The S4 is a sports sedan - quick but without new springs/shocks a bit heavy in the handling department with lots of nose dive on braking and nose rise on acceleration.

However, aside from those who have chipped I know of no one who has had a turbo die on their S4 that hasn't had it covered under warranty, and further Audi seems to have fixed the problem in 2001.5/2002 S4s (I don't know what year you had.)

I know exactly what you mean, though. I traded my Audi TT for an S4 because I thought I would be more comfortable in the S4; three weeks later I traded the S4 in and bought my own TT back (not a recommended financial operation...)