i upgraded my S2k wheels to 18" oz Superleggeras, and had my Geo done by Dixon motorsport. with the bigger wheels, wider tread and lower profile tyres it actually made the S2K a far more responsive car. in terms of increased grip and feedback. must have just been enough to take the raw edge off the stock setup.
compare that to the zed because of its weight it was far more forgiving. like suits said i reckon it was a bout a 3 second difference between them on reaction time. you can still get it wrong in a 350, but it wouldn't punish you as much as the honda did if you mistreated it. its why the S2k has a higher insurance, even though its marginally slower. and it picked up the nickname widow maker.
but that's why i think i had more fun the s2k than i ever did in the zed. the zed felt to safe and sensible. to get it to the edge you had to push really hard. to a point that with most drivers their skill would run out before the cars did. you could drive it without really having to try. it made even bad drivers look good. but the S2K you really had to think about it, match the gears and the revs, the speed, balance the throttle, and when you got it right it was beautiful.