You know, I almost made this thread, but I felt too noobish already with my thread-whoring so I held back. I'm glad you did for me.
Anyway, I find it a bit silly personally. If you wiegh the benefits of solid-axle with IRS, one will be clearly superior, and it won't be the axle. In
ONE aspect of things, the axle will be EASIER to make better, and that's only hooking off the line. In all other aspects (weight, ride, handling, etc) the IRS is far superior. An IRS can be made to hook just fine. It won't lift the nose off the ground more than a couple times (or once for that matter) before CV joints start to break, but if you're building a purely track car that is even putting that much to the ground, then you're going to probably put an aftermarket axle in anyway.
I really like the idea that it will have IRS...if only they would go with a transaxle set-up (C5/C6 transmissions on the rear axle vice the flywheel) then this car would be able to handle like a monster....then again, this isn't the legacy of the Camaro, per se.
Just my humble opinion.