I've had an old M8, FX-II, VX III, and VX-3i.
The light gathering and clarity upgrade between the VX2 and VX3i are worth the extra money to me. It has nothing to do with allowing you to shoot before or after legal hours - a better scope does not make anybody a poacher.
Much more to do with sharpness of picture at higher magnification in lower light conditions, making it easier to pick out the details when you're trying to find that tiny shooting lane through the brush. But if VX2 fits the budget better, by all means go for it since they are great fit the price. I believe the current line of VX2 scopes are every bit as good as the older VX-III scope I have, if not better.