iI have had both models as well, Z3, VX3, concerning the mounting length on the 2.5-8 Leupy, I have several mounted on rifles in the safe, 3 of them are on full length Magnum rifle actions. It has been my favorite hunting scope for many years for all around use on a hunting or stalking rifle. They are both excellent for the intended purpose, if you can swing it, get the Swaro, its a great scope. If funds are an issue, get the VX3, you really can't go wrong either way. Low weight, reliable, high speed, low drag.