Optically I would say they are on par, fuctionally I'd say they are in different categories.
Doug,
How do you mean functionally?
Are you comparing a Vortex 12X to a Vortex 15X saying they are not interchangablefor glassing long distances or are you comparing the Minox 15X with the Vortex Kaibab 15X (which I was curious about myself)?
I am wondering if my eyes could discern the 100% better performance the price difference implies.....
What do you think....