Dont know if I'm to late on your post but Haveing owed a swarovski 3x12x50PH which is now a discon. model. I dont know why. for hunting at low light magnifing reticle you just can't beat, I than also tried Schmidt & Bender 3x12x50. I decided to compare the to so no better time to compare lowlight capabilitys than at night. Over looking a field on a clear night both scopes could see in the open. The diffrence was along the woodline. The Swaro. I could see the edge, but thats was it. The S&B I was able to make out object along tree line such as tree limbs some trees etc. Swaovski is a great scope. I dont like their new reticle in the second focal plane for two reason one I hunt till the last min. when it get a little dark in the woods I turn the mag up to about 4-5 power And I can see the cross hairs just fine. the 2nd is and i spoke with swarovski on this when you have a second focal plane reticle accuracy is only good for what ever magnifiction you are shooting at for what range. (They will not garuntee accuracy!) A first focal plane reticle magnifies the crosshair in the same portion as the target. Now S&B garuntees the scope for 30 years and the garuntee accuracy.
Haveing said that I would'nt go with the Z5. I would pay the extra $250-300 and get a Schmidt Classic 3x12x50mm or even 2.5x10x56 A7 reticle. You can get a turret put on the scope just like there percion hunter model. for an extra 200. That will get you out 500 plus. and you''l have a 30mm tube scope with plenty of power for 500yrds. 18 power is alot. Marine sniper day scout scope are 3x12 and they shoot at 1,000yrds. better quality glass means you have to use less power. S&B is a little heavier scope, they are biult like tanks. Plus usually you get more out of better quatliy. Hope I helped you out some