My opinion will stay on the road course as well.
The Cobras IRS is a great addition for the twisties over the old live axle.
I am a Mitsubishi fan through and through (only sports cars I've ever owned) but for 30-35k, Cobra all the way.
Straight line or a road course.
Like I told my last wife, I says, "Honey, I never drive faster than I can see. Besides that, it's all in the reflexes."