i have 18" kumho asx on my bimmer and am pleased w/ its low noise, overall grip in dry/wet/snow and think it's a great deal for the $.

i need new tires for my S and wonder how much better the pirellis are over the kumhos? how much better are the pirellis for extra $110 for the set?

pzeros ranked #1, asx ranked #5. but some ppl seem to have balancing issues and tramlining issues w/ the pirellis.

 

Hey I dont know if this will help, but I had a set of pirelli pzero nero m&s on my prelude I just sold. My father also has them on his '03 Saleen SC (which is sweet) and I have driven it. I was pleased with them on both occasions they were very sticky and not prone to break loose on turns (unless you try). Granted that may not help you since I never had them on the s2k, but I was very satisfied with them on the lude. The wet traction was amazing by the way.

 

For what it's worth, I'm on my second set of Pirelli P-Zero (not M&S rated). I got 9000 miles on a pair of 265x18 rears: terrific grip and low noise. Never had a set of Kumhos, but are considering them for my Acura TSX when I upgrade to 18's next Spring...

 

On the OE 16" wheels they really do not make a good size option for the S2000. The do have the OE 205/55R16 and 225/50R16 and while they would work better in the winter they will not be nearly as good in the other three seasons.
If you are not an aggressive tire they would work fine. Otherwise not a good tire for the car.
If I can help let me know.