The car felt more peppy in lower rpm but it doesn't really do anything for the throttle delay directly. Its an inherent drawback of the drive-by-wire throttle.
That said, I never thought the throttle delay was very bad on my Z. I drove a ferrari 599 this weekend (a 1 hour "DFW drive your dream" gift from a family member) and it had more throttle delay than the Z
. It was a blast to drive though.