Owning a Vari X II in 3-9X on one of my Remingtons I can second that opinion.
No longer offered by Leupold as the Vari X II as of a few years ago, it is made now and labled as the Leupold Rifleman and modified with a slightly ergonomic shaped tube. Both are a great quality scope at a very reasonable price.
There can be too much of a good thing with antler rattling.
I like to hit the horns together for a good 30- to 40-second rattling sequence and then hang them up and resist the urge to hit them again.
This works to the hunter's advantage, because if a buck has heard it, he may have been 300 or 400 yards away and he comes in and he's not exactly sure where it came from.
When finally is time to rattle again throw a slight change-up into the routine.
The second time, don't rattle as loud...