My new A3 is an sline with sport suspension. Even though its got a shorter wheelbase and larger wheels I find the ride to be as good as if not better than my old 8p SB. Its also much quieter inside.
As someone else pointed out, comparing an A3 to a 3 series isn't fair. Its like comparing an A1 to an A3. For me, the new 3 is a better driver's car than the A3 but to configure it to the same standard it costs much more.