I only really listen to the first CD... World Ov Worms, and two songs from #2... Zyklon Aeon, and The Prophetic Method, oh... and obviously Dominate. Beyond those... they came into the world like Hate Eternal... with everyone knowing the founder's pedigree and legend (Samoth from Emperor became Zyklon, Eric Ruttan from Morbid Angel became Hate Eternal), and both around the highest point in their former careers... they laid fucking waste from the first song on the first CD to the last, then just kinda went a bit stale from there. Disintegrate, just like King Of All Kings... was more just basic death metal, and the third CD's just kinda settled into the rest ov the genre with nothing standing out. Conventional death metal bored the shit outta me.
I think Samoth just really needed Ihsahn to bring it out. If you like the really good Zyklon shit, the check out Emperor - IX Equilibrium. Ov all the Emperor CD's that one was largely Samoths... and easily the best. Ihsahn is more experimental ov the two... and left to his own devices can get downright weird. Zyklons best work came directly after he left Ihsahn and Emperor broke up. Ihsahn is the same way... he's done some really cool shit since, but the power... is just not there.
Vredesbyrd is not my favorite, but a good one, though when its live it becomes insane. Dimmu is at their most powerful when Vortex is singing, period. All 'his' songs are on my lifting playlist. They will NEVER be the same.
Vortex was would set Dimmu apart, there last album I was not impressed with.
Checking out IX Equilibrium right now