A bit surprising, those pulls.
...also going to be VERY interesting to see this comparison head-to-head on a road course. The Viper will be more difficult for a moderate-to-less-skilled driver. And, to me, that's fine. The Z06 will have the trans advantage, even for the manuals (with their selectable rev-matching).
NA, the Viper will run all day hard, whatever the temps. Give that Z06 a hot day and I'll bet you get maybe half a session before it starts to de-rate. And the Viper TA 2.0, with added aero, will be even better on the road course.
And there's the ACR, most likely in 2016 IMO. Endgame.