Unless I am reading the specs. wrong on the Z5 the light transmission is only 90% and it does not have very much elevation adjustment probably because it has a 1 inch tube.
Nikon advertises that their scopes have a light transmission of 95%.
This site is mainly for long range shooting and it seems to me that the Z5 may not be a good choice for long range shooting.
For about the same price you could get a NF with a EBR 1 or 2 reticle and then get a custom turret matched up to your rifle.
For about 1/2 the price you can get a Vortex Viper PST FFP scope with illuminated reticle.
I have a 6-24x50mm PST MOA with illuminated reticle and a custom turret. I think it is a very good
long range scope.
http://forum.gon.com/showthread.php?t=564977&highlight=
http://forum.gon.com/showthread.php?t=574886&highlight=
Just my .02,
joseph
PS: By the way I am not affiliated with Vortex in any way.