Clarificaton:
I own the Viper HD 15-45x65 Spotter. For hunting, it is a great balance of weight-for-glass quality, as well it is great glass-quality-for-value in a spotting scope. I then began to utilize it for my long-range precision shooting, and found that I would benefit from the mil reticle eyepiece, which is only available in the Razor x85 model. However, the Razor x85 is much too heavy for mountain hunting.
In my opinion, a reticle eyepiece for the Viper line would be a great addition. Vortex recently offered a lighter Razor x50 but it is also not compatible with the reticle eyepiece.
Hope that clears it up.