Not sure this will help or not, but I was running dual EP500's and sold them both as I switched back to HSU subs.
The EP500's never disappointed me in the home theater department, but they were a major disappointment to me in the music department. I just didn't find them to be as clear and detailed.
That said, I'm a former studio musician and therefore I'm anal as hell when it comes to the quality of sound.
My vote would be for the HSU. It rules in both home theater and music (IMO), and has yet to disappoint anyone that's owned their subs. At least to my knowledge.
