When you go to an Opeth gig, your expectations shouldn't be based on what they would usually be for a metal show. A lot of people have that 'snoozefest' complaint, but it's usually because all the bands that precede and follow Opeth on the stage usually have more of an energetic vibe about them. Opeth have always been about dynamics... it isn't a constant thrash fest that you can keep a pit going to down in the crowd.
The gig they played here last March was quite easily the best gig I've ever been to, simply because I understand the music, I can take in the vibe, and enjoy myself on a much higher level than say... I did when I saw Deeds of Flesh and we were all kicking each other in the head.
Ghost Reveries is quite easily the best metal album that's come out this year IMHO, despite how much I love Blut Aus Nord's EP. Maybe not even just this year, but even after Blackwater Park.
Sure you get the releases from Kreator and Nevermore and such that really kick you in the face and say 'fuck man, that's some good metal'... Opeth slay on a whole different tier of music. There's just been those indescribable elements to their music that keep me coming back... the fact that they always change, yet you can still recognize them as 'Opeth'. Listen to Orchid, then listen to Ghost Reveries... I mean, holy crap... Other bands are still pushing the 'metal' thing, rehashing themselves, and they ultimately just continue to sound like their old stuff... Opeth totally reinvent themselves on every release, and it's this diversity, both between the albums, and throughout the songs themselves that keeps people so hooked.