If this were me, it would be the Dimmu show....for Enslaved. As one of my all-time favorite bands, I would support them every time they come to the States if I could.
Plus, the new album is a HUGE step up from Vertebrae, in my opinion, so it'd be cool to hear some of those tunes live. Dummy Burger, I'd check 'em out for a while, and if I wasn't feeling it, I'd bounce. A Vortex-less Dimmu Borgir is not one I'd enjoy for too long, in all honesty.