The first line of Slipknot's record-company bio says the band was "born of the near-desolation of Iowa." Since the act was actually founded in Des Moines, which isn't exactly a post-apocalyptic wasteland where water is hoarded and children prefer eating their pets to playing with them, this description is patently ridiculous. Then again, hyperbole and theatricality have always been part of the group's appeal. Using numbers instead of names (a gambit the members are wisely downplaying) and wearing allegedly ghoulish disguises (which they're shrewdly still doing) may be silly and adolescent, but we're talking about metal here, not Oprah's book club. Despite such shenanigans, moreover, Slipknot is continuing to make sonic improvements. Last year's Vol. 3: (The Subliminal Verses) is far and away the masked men's choicest disc to date -- bloody and visceral, yet featuring a more controlled attack -- and an enhanced version of the set hitting stores this week includes a bonus disc replete with live tracks, extended or remixed renditions of Subliminal material, and a couple of decent new tunes. If Slipknot keeps progressing at this pace, the players, who are gigging with Lamb of God and Shadows Fall, won't need to rely on shtick much longer. They've done Iowa proud -- or what's left of it, anyway.