It really is apples and oranges. But overall, the S is the car I'd pick. Drive both of them and see which one you'd rather have. The IS will have a little more low-end grunt and it has WAY more power potential, but the S will have similar power delivery to the GS-R and has the potential for more than enough power

Also, the S2000 community in this area is VERY tight. Maybe that's why it seems like we're everywhere. We do a lot of stuff together.

BUT, if you care about people on internet boards bashing your car even though they've never met you and probably never driven one, don't get the S.