Let me start by saying that I'm not a driving expert, AND I'm not much of a writer, so take my comparison for what its worth...
I've always been a fan of the Corvette. The Z06 was a very nice car, and relatively inexpensive. The biggest differences in the cars for me are torque and steering. The Viper has tons of power in practically every gear at nearly every rpm. The Z also has great power, but it responds better in the upper rpm range. Also, I didn't have to think about driving the car as much as I do the Viper. I guess the Z06 seemed more civil, if that makes sense? I went from the Z to the 996. Same thing, less power, much better fit/finish, smoothest transmission of anything I've ever driven. Ultimately though, just too refined for my tastes.
I never thought I'd have so much fun driving a car as I do in the Viper. I can see why so many Viper owners have more than one. After I finish my nut/bolt restoration of my 62, I may look into getting a GTS. In the meantime, I'll definitely want to do the VOI next year and go to driving schools if we have any available to us.