It's an odd one, the last two-and-a-half minutes are one of my favourite bits of the whole sessions but the first 10 minutes do nothing for me.
It has something that I really like in music: it pulls me in with repetition/gradual changes and doesn't let go. (Swans gets to me in a similar way, bring the sun, she loves us, mother of the world, etc) On top of that it sound more mysterious and less like something I can understand, if that makes sense, as it progresses. That's what gets me. Feels good to put it into words!