The difference is that in the Zed, although I never ever lost control even for a second, there is always that little thought in the back of your head that the rear end might feel like going somewhere it likes . I loved the thought that it was always possible, but never worried about it.
In the S5 it's noticably faster in acceleration and lighter too, but with 4 wheels planted (albiet 60-40 split) you never feel like it might slip.
I've seen them sideways on youtube, but basically only when being hammered on a track........
I love the Audi, but know ill be back for a Zed at somepoint, if only when the recession lifts and I want a real cheap toy.
Oh and the Zed turned more heads (probably the gold wheels ) although until you look at mine close up you'd probably think it was just an A5?