both are great handling machines. The s2000 revs forever and the z pulls strong all the way past redline.
I think that both cars are great. The Z having the larger engine is obviously more powerful. The S2000 is a tremendous handler right outta the box. I've seen articles claiming that changing the suspension set up will actually make it handle worse if not set up properly.
Personally, I go with a Z. I'm biased and a Nissan fan so of course I'd say that. But if I got a S2000 handed to me I wouldn't say no.