lyrics are teh win. it's a shame that Mikael writes Opeth's lyrics the way he does; that is, intent wise. If he put lots of thought into it, it'd be kinda cool cuz then you could dissect them and try to figure out what they truly mean.....if he just wrote random words/topics it'd be cool because then your own interpretation would be left completely open.....but he writes the lyrics with general ideas in mind....and that sort of takes away the fun a little with me....it means you can't interpret your own grand meaning and there isn't all that much to go digging for; ie, the lyrics are mostly just there for being and sounding pretty. Which, to me, is a shame.
But other than that minor quibble, Opeth's lyrics are pretty good. =) Maybe not with Opeth, but I find that understanding how the lyrics are structured and expressed in the song's vocals helps to understand the overall structure of the music. A handy tool for dense death metal.