Hmm, well something worth bringing up is that this recording is quad-tracked, which naturally makes the guitars sound thicker and smoother with a squishier attack (due to the human error between the takes).
If you want to achieve a sound such as Adam D's signature massive wall of rhythm tracks with just one guitar, then a pickup like the Miracle Man or Warpig will get you there no doubt.
If you're interested, this is what just one of the guitar tracks sounds like:
http://dl.dropbox.com/u/790683/Swedish%20B2%20single%20GTR.mp3You can really hear the more dynamic attack (as in, you can hear a fair amount of inconsistency in my picking :lol: ), and really extreme clarity on the big open chord in the second riff.