The NSX is only faster than the automatic Corvette with the stock axle. All 6 speed Corvettes are faster than the NSX as well as the automatic with the "performance axle".

The Z06 is significantly faster and will also outhandle the NSX.

I know, I'm an SCCA auto crosser and I had an NSX. My Z06 on the same tracks is about 3 to 4 seconds faster per lap.