Wish I could remember exactly which GT500 review I read, but the author (who didn't dispute the claimed HP numbers) said he felt that
"all of the ponies weren't running in the same direction". I found that to be pretty interesting.
Add to that the fact that the Challenger will have 4 wheel independant suspension, where the GT500 has a "live rear axle", and the Challenger should punish the GT500 on the twisties as well as the 1/4 mile. Remember .......174 mph aerodynamic restricted top speed on the Challenger - not sure what the numbers on the GT500 are (and I really don't care).