This stuff is all over the place. Road & Track, if I recall, in a moment of weakness admitted that the Z is slower than the SRT. I believe the new "Automobile" shows numbers certainly no better than the SRT. MT has numbers that make no sense other than for effect . Hopefully, someone will get a skilled driver, a Jeff Gordon, or a Jeremy Mayfield (may not be fair he has Vipers) or someone similar, put them in both cars, the same day at the same track under the same conditions and we will see.
Every new hot rod is the "second coming" according the car media then after a period of time , familiarty breeds contempt and they move on to something else. In truth (and I just came out of a C6), no Vette has the fit, finish, pananche, and I doubt speed of a Viper. And as I have said before, as much as I would like to have a Z06 ( I took myself off the waiting list and got the SRT), the rubber will meet the road when you take that puppy into the typical bowtie dealer for service and the 18 yr old kid starts pulling out the shop manual--good luck. I had to show my Chevy tech how to start the C6 and did not have much better luck with my C5. I have had 3 Vipers and the same Viper tech for all three who can work miracles blind-folded.
In terms of appeal, forget about it. I had one of the first C6s around and never hardly got a second look. Most saw it as just another Vette and the die hard Vette guys were so conflicted about the new styling they would downright ignor you. Similarly , the average person won't disguinguish a regular Vette from a Z. TMB