Well if you are going to bring the ZR-1 into this, Dodge is producing a Viper ACR. Though with the probable high weight difference between the two, I'm thinking that battle may belong to Chevy.
The Hennessey driver might have been overzealous with the throttle and bad with turbo lag. The Viper Venom isn't that difficult to drive from what I've heard. As I understand from most reviews, the Viper is considered the better handling car. It usually scores the higher lateral g rating, and isn't as prone to wild oversteer as the Z06. The Viper's understeer was heavily revised and reduced for 08 and it can be overwritten with throttle steer whenever it gets in the way.