just for clarity, vipers and srx's are completely different sleds. hard to even compare them in the same sentence. stock for stock, a viper wont hold up to an srx in a straight line, but the srx cant take the bumps and ditches like the viper. however, the 02 viper had some issues with suspension calibrations and depending on how particular you are, you may or may not notice. yamaha addressed this issue in the service bulletins.
choosing between the rx and the viper, hands down the viper, for what you describe as your riding style and what your accustomed to riding. similar ride and feel to the sxr, equivilent to your srx only like it was on steroids when you hit the happy flipper.