Replying to AR5 + binding weight, hmmm

I have two pairs of skis right now.
176 05/06 AR5s with rossi axial 120s
185 06/07 ARVs with salomon z12s
Now, i have found that my arvs are much, much lighter than the ar5s. Before bindings went on though, i thought they felt similar weight. But, the axials are a pretty heavy binding compared to the z12s which are apparently one of the lightest bindings on the market right now. Will new, lighter bindings (probably next year) on the ar5s make a big difference in weight or should i just leave them like they are? Not a huge deal because i can spin just fine on the ar5s and stuff, but i would really prefer a lighter setup.