Why not comment on the videos I posted showing the fastest possible times for each car. Who cares if it's the same same same, it's easy to lift the throttle when you choose and definitely he knows how to handle a viper better being MOPAR employee. If you're looking through a filter, that's all you'll want to see. Take that filter away and you might be surprised what else you see.
Give both of those cars to a GM test driver and see what the results are.
"Same same same" is a HUGE deal. Track prep, driver skill, elevation, humidity, temp, etc all make a difference in how fast you run. I'm not saying this because I'm a "Viper' guy. I've had Vettes in the past like a lot of people on here have, and the Z is one hell of a car.
Twister brought up some really good points as well regarding how many of each car out there and the fact that a lot of the Gen III's are verts, which makes it even harder to run good at a lot of tracks because of safety regs.
Any time you line up cars with this kind of hp at a track, it's almost always a driver's race. The driver still makes a pretty big difference on highway rolls too. Knowing what RPM to get the best jump from, shifting quick, etc can make the difference in winning and losing.
My neighbor has an '08 (I think) Z and we mess with each other whenever we see each other out. Neither of us is completely stock anymore, but on highway pulls I usually have him by a car or so. Of course, I know to shut down at the top of 4th because as soon as I hit 5th, he'd be coming right by me.