It comes down to what features are worth to you. Different configs and reticles etc.. I chose a Vx3 because I wanted the brightest thing possible and am happy with the choice.
This might help.
From the Following link at
Riflescopeinfo.com Leupold VX-1 lenses coated with implementing of Multicoat 4 technology that allows 92% light transmission. Elevation and windage are finger click adjustable with ¼ MOA increments. Adjustment range is 52 MOA. Main tube is made from 2 pieces. VX-1 rifle scope has classic focus eyepiece and tactile power indicator. Currently there are 2-7×33, 3-9×40, 3-9×50 and 4-12×40 models available. Price range is $209.99 – $299.99.
Leupold VX-2 lenses coated with index matched Diamond Coat and have blackened edges. All these allow 94% light transmission. Main tube is made from 2 pieces and has 1 inch diameter. Adjustments accomplish by finger tips with ¼ MOA clicks through 56 MOA range. VX-2 rifle scopes equipped with externally threaded fast focus eye piece and tactile power selector. These models feature 2nd generation Argon/Krypton filling that protects your scope against fogging with rapid temperature change.
Some of VX-2 models equipped with the adjustable objective (AO) and some with custom dial system (CDS). When you buy CDS model you can order a custom dial knob from Leupold for free. This knob will have numbers that refer to the yardage for specific cartridge that you use. Thus all you need is to set your scope to appropriate yardage and make a shot. There is no need for elevation adjustments and holdover. Leupold VX-2 scopes are priced in the range of $299.99 – $599.99.
Leupold VX-3 lenses feature Xtended Twilight System and Diamond Coat 2. This coating optimized to transmit more light in the blue violet color spectrum. Blue violet color dominates in twilight. Thus VX-3 allows 98% of light transmission and provides you with the bright and clear picture even in the early morning or at the dusk when the game is more active.
Main tube is made from a single piece and has 1” or 30mm diameter depending on model. VX-3 scopes are filled with Argon/Krypton gases. Adjustments are easy to perform by your fingertips with ¼ MOA clicks through 58 MOA range for 1” tube and 116 MOA range for 30mm tube. VX-3 equipped with extreme fast focus lockable eyepiece and tactile power indicator with range estimation.
