I've used one on my Js10th for a while.......i still have it by the way. But i no longer use it. I'd rather go the distance to install a fernandes sustainer system
like steve vai
has in his guitar..........for sustain, ive been meaning to do that for forever.
The difference, if any, is barely noticeable at least it was that way with me.
It might give better, more significant results, on other guitars..........for me, i only play Ibanez Js's