I am having a tough time deciding between the two illuminated scopes.

Price is not an issue as I can get the Leupold for about the same price as the IOR....

My rig will be a Colt 6920.  I want to go from urban to 600 yards, so I like the ranging feature of both scopes.  I don't plan to run night vision on the rifle.  

If the SHTF one will not be able to send the scope back for repairs.  So I want something that is industrial strength.  Night clarity is very important

I will try to find a LaRue mount.

Please give me your thoughts

industrial strength sounds like Leupold.  

Urban to 600 sounds like IOR.  

Leupold glass has less effect on color's in my very limited experience of one Ior scope, (several LEupold MKIV series sights) and I preffer the color transmition of Leupold glass.

Ior's new reticle is far ahead of anything at Leupold though for an Ar.  

Tough choice.  I can't answer it other than to say you won't go completely wrong with either.  

Minority opinion here but I don't like Larue SPR mounts as they mount about .15 (or so it seems) higher than I want the sight to mount- I lose my cheek weld and speed that comes with that cheek weld.  I'ld be looking for a set of Larue rings at a better height.  I bought an old set for cheap and really like them (they provide that slightly lower mount that matches the axis of the iron sights)

Quoted: Minority opinion here but I don't like Larue SPR mounts as they mount about .15 (or so it seems) higher than I want the sight to mount- I lose my cheek weld and speed that comes with that cheek weld.  I'ld be looking for a set of Larue rings at a better height.  I bought an old set for cheap and really like them (they provide that slightly lower mount that matches the axis of the iron sights)

Here's my opinion based on my personal experience...

I have a BIG HEAD.  The Armalite 1-piece is just too darn low for me on an AR15.  The LaRue mount is the perfect height to allow me to get my mellon in a comfortable spot for good cheek weld.  With the Armalite (1.35" compared to 1.5" for LaRue), I have to squeeze in and look down.

If you are a normal human of average proportions and like Armalite, you may not find a good spot with the LaRue as it may be too high.  If you have a coconut head like me, you probably will find the LaRue just about right.

YMWV