Soooo ... looking on the internets, it appears as though there are at least 9 different catalog numbers for It Takes a Nation of Millions to Hold Us Back. Even just looking at images of the label, you can tell there are differences -- most obviously, some have the Columbia ring, others don't. But there seem to be other variations, too. I presume this can mean there are different masterings, too? And, if so, anyone done any testing, or have a mastering to recommend?