I think that was the highlight of the game for me, which is kinda wild because I only went on a whim. My story wasn't pushing me in that direction at all, just figured I'd poke around. Great fight, too. I'd been steamrolling everything for most of the act by that point, so it was nice to get challenged again.
The song was a pleasant surprise too. That, the harpy song, and the Ketheric/Gith battle music are going to be stuck in my head for a while.