That's exactly why I like it. It's kind of a anti ambient droning that defies being music, but is well done. They are tight and obviously they are talented. i can't tell what is bass or guitar and yes the scemo vocals take some getting used to. But heh I like captain Beefheart as well which is another odd time signature syncopated oddity. Melt Banana is another odd duck I like.
What I think I like about it is it takes the idea of metal and purifies it into low register pounding without cliche verses, choruses or rap interludes. Metal in its purist form?
The first time I heard them all I heard was noise, the next it started to grow on me, like a tumor!
I remember when SOAD came out, people had the same reaction to them.