Well, for one its cheaper than buying a new scope with this feature on it to replace what you already have. Plus - if you mean the Custom reticle or the custom bullet dial or both, the Custom reticle for specific ammo is nice plus its the only one they will do in a Vari-X III or VX3 that is like the Long Range reticle which is great - the Custom shop one is specific to a caliber and bullet actually, so don't do it if you swap scopes much. But for the cost its a great deal, I had it done on a VX3 I have on my 280Rem and sure like it better that the standard duplex or a B&C duplex, plus with the dial its pretty slick.