Dude I'm in San Francisco, but I'm still going to San Diego rather than LA. So I don't see why you're going to the LA show. They'll be opening, at most maybe a 40 minute set, I'm guessing?? Plus the ticket will probably cost more.
I've never really listened to Nile or Meshuggah (thought I've heard of them and some of their music), but I'm not dying to see them anytime soon. I know Danzig, of course, but I hardly care for seeing him. If I went, it'd be just for Opeth. And like I said, it'd be a short ass set. So I'd be spending more money for less Opeth... If that's not backwards thinking, I don't know what is...
So I'm willing to drive the extra two hours (actually me friend is

)to go see a
full Opeth set for less $$$. Plus I enjoy Lacuna's Coil's music, and I'd rather see them than any other bands in the LA show.
Good thing I got family in the valley though (where I'm really from), I'll be stopping by Fresno for a night, the night before the show; it'll make the trip a little more bearable; plus I gotta pick up some friends.
Honestly, I think you're better off going to the San Diego show; if you want, go to both, but you'll be spening a lot more money than you need to, to see less of your favorite band...