I have or have had every generation of the Vari-X III, VX-III, VX-3, and an old Vari-X II in both 40m and 50mm objectives, with magnification ranges in 1.5x5, 2.5x8, 3.5x10, 4.5x14, and 6.5x20. I also have a Swarovski A series 3x9 1" tube, and a Swarovski PH 2.5-10 30mm tube. The Swarovski PH was their top scope a few years ago until they refreshed the product line and replaced it with the z5 and z6. The PH retailed for $1500 for comparison. I have very good vision still and pretty good night vision. Having used all the scopes listed, I can honestly say that the only scope that I felt there is a noticeable difference that I could really see is the Swarovski PH. It cost three times as much so I would hope there was at least a little difference.
Don't over think the glass, the current glass on both the VX-R and VX-3 is so close I don't feel you would be able to see the difference, I can't at least. Go with the scope that offers the features that you want. If you think the illuminated reticle is something you will use get the VX-R. If it isn't then get the VX-3. We hunt at night here with lights and the red dot of the VX-3 illuminated, or the VX-R is awesome. If I wasn't hunting at night, I would get a VX-3.