I threw a friend's Meat Box into my chain once for a set, and maybe it was just the lack of a foldback and the small bar PA etc, but I had difficulty hearing any real difference. I spose it's meant to be something you can feel more than anything, but I didn't notice any real thickening of the sound.
Maybe I'm missing the point of it, but does anyone use one in any particular way or with any particular gear? I'm tempted to get the reissue one day if I'm convinced it'd be worth it.