I've never driven a 1.9 Z3
I cannot imagine its better than a mx5
Try it. 50kg~ lighter engine makes hell of a difference.
It could have been difference in camber, but neither NA nor NB's steering felt as precise as the Zed I have.
Lap of Central circuit with a quite heavily modified NB8C (4.3 Cusco 1.5way, Tein coilovers,etc..) on slick tyres. Notice the maximum straight line speed on NB8C is 157km/h for the main straight and 141km/h for the back straight. This is with a considerably higher cornering speed (= higher exit speed.)
Below is the data of one of the laps on my very first track day at the very same circuit with the Zed. Not on slicks, just some good old Ventus R-S4s on stock suspension. Yes, it understeers a lot with the stock suspension, but you can see that the car picks up pace fairly quickly regardless.
On the other hand, I will be putting in M3 3.0's LCAB real soon for the ultimate track setup as well...

Can't wait to feel the difference in feedback..