I read somewhere on Joe Seigler's Black Sabbath site (I'm guessing you guys are familiar with it) that there was a "good" mix of the Born Again album, but then Geezer screwed it up and Gillan got really, really pissed and then split. I've also read that Gillan needed teleprompters at the live gigs because he never even bothered to remember the lyrics, and at the very first gig all the smoke that went with their stage show obscured the screens so he just did a bunch of his patented "YAAAAAAAAA" 's. All this, plus their goofy Stonehenge set, PLUS lip synching on "Don Kirshner's Rock Conert", PLUS the "Trashed" and the "Zero the Hero" vidoes basically made this band one giant misstep. Too bad, too, because there were some solid Iommi riffs on that album.
BTW, I'm not trying to slag this particular incarnation of the band, it just clearly had its flaws.