hrmm...well since I still had my coaster collection handy(lol!) I decided to try it with the rdx_manager instead. For those keeping score at home, I'm trying KOF XII burned on various media with both imgburn and nero.
At any rate, still no go. Got the eboot error as expected.
Also, I did try booting one of the HD with the copy inserted and while it attempted to boot, it nonetheless stalled at black screen, which as I understand from reading around, is not at all unusual at this point.
So, there's some more input, for what it's worth.