i've just swapped from a 350z to an S2000, there is a big difference between the 2 cars same as with other high revving hondas, and the cars require different driving styles.
i'd really recommend you go out and get a decent test drive. my first experience of a Zed test drive was a let down too, but thats cos i got to go in rush hour in heavy traffic, for 10 minutes.
2nd time i went out for over an hour and got to do a range of roads.
the Zed is very capable, the reason it might feel slower is that its so good at what it does you don't tend to notice it. the acceleration is so smooth as is the power delivery that it removes that manicness to it.
lot more torque with the zed, pulls in any gear with real ease. excellent cruiser; well worth the ownership