There are 3 drivers in the article. An enthusiastic drive, a club-level racer, and a professional racer. All three drivers had the faster laps in the Z06. The ONLY one who preferred the NSX over the Z06 at the racetrack was the 'enthusiastic driver' with NO race experience (whose write up also included references to Gran turismo 3 and 'which car he'd prefer on a date'). What does that say about your opinion, since you DID post this article?
I have driven a few laps in a friends '96 NSX at a parking lot autocross last year and was impressed (considering he only paid $35k for it). I test drove a used '01 Z06 early this year, and it was definitely more powerful and, from the few curves I went around (at least in straight out lateral acceleration, no transitions), seemed to handle at least as well.