Comm'on Guys... I'm going to say its not a "fair" comparison. For only one reason. The Camaro structure was designed to handle over 500 HP. I'm guessing the Genesis wasn't.
Having a structure capable of over 500 HP greatly changes the amount of reinforcement and the gage of many of the body sub-components. If the Camaro was designed to be a V6 car capable of 300 HP I'm guessing it would weight significantly less.
(And please don't say, that GM should have made two-different bodies to reduce the weight of the V-6. This would cost a litteral fortune.)
I like the Mustang/Challenger/Any other V6 equipped car that is capable of over 450Hp. Comparo personally...