Incredible.
Shane, I don't even listen to Sunn O))) at home, but I'm sure you're well-acquainted with the fact that they are a band who can only really be seriously appreciated live. I've only seen Sunn O))) once before and that was a straight drone performance, which was fine and all, but worked more as an endurance test and an experience than as anything genuinely enjoyable from a musical standpoint. I felt the straight-up gut-shaking stuff benefited far more from the presence of something with a little more light-n-shade, including some moments of actual, genuine beauty (after a fashion).
Also, I had the privilege of getting to view the show while standing alongside one of the paths to the entry/exit, and it was a great joy to take note of all the people leaving midway through the set. Also observing all the people entering without any ear protection, and thinking about just how truly fucked they were about to get.