Just posting it for people reading that do not know what the differences are in the old Vari X-III and the new VX-III.
The new index matched lens system uses specific coatings for specific lenses and yes this does increase the light transmission. A light meter can see the difference but in order for you to see the difference you really have to look close and use resolution charts. The average Joe that picks up a VX-III and a Vari X-III to haul to his deer stand and shoot three times a year won't see any difference. Avid hunters and shooters that really use their stuff will see a difference in the optics and appreciate the new features.
The finger adjustable windage and elevation is a big improvement that was long over due and does make a difference.
The lockable fast focus eye piece is also a much better design than what they had.
The new reticles, side focus and new scopes are also part of what makes the VX-III better than the Vari X-III too.
Basically Leupold is just catching up to what the competition is doing. Elite 4200s, Grand Slams, Monarchs and Conquest woke up the sleeping giant. I think Leupold will continue to improve their existing lines while launching new and exciting products.......just hope they don't further price themselves out of the market.