I finally got around to installing one of the ESP Arming Adjusters in my RG8670, and man, I gotta say that it made a HUUGE difference. Took me a while to figure out how to set it up properly but now there's more tone and sustain on it than I could ever really need. The guitar is all of a sudden acoustically more vibrant and there's so much energy transfer from the strings to the body that I can feel the vibes run through my fingers as I tune it up, and I'm not talking about small vibes here either.
Striking an open E and just placing my hand on the tuners feels like I'm holding onto a grand piano striking the same note. As much as I used to like the Ibanez Backstop, not only is this ESP arming adjuster cheaper but I find that it does a better job than a backstop.
Before everyone starts ordering one for thier guitars I must add that installing it ISN'T easy. Rich (Ibanezrules) got his shipment of ESP arming adjusters around the same time I got mine and according to his site it *SHOULD* fit a Jem(and guitars with the same cavity route). Unfortunately I couldn't get it to fit without doing a bit of routing. (Rich, if you got it to install without any routing please do let me know)
I tested this on my RG8670(Edge pro), RG1880(Lo-Pro), UV777bk(Lo-Pro 7), as well as my Usa Custom(Edge) and a friend's Jem 7VWH(Lo-Pro). NONE of them fit properly. The recessed cavity which was designed for the Ibanez Backstop is about 1/2" short length wise.
Here's a shot of my RG8670 with the arming adjuster installed (warning.. VERY VERY BAD picture quality).
Here you can see the recessed cavity as well as the Arming Adjuster. (If you're wondering what that black thing is in the control cavity, thats a passive mid cut that I built so I can cut back the mids on the overly middy TZ).
Summary: Ibanez J-Custom + ESP Arming Adjuster = "OMFG!! I almost creamed myself!!"