For music: Towers without sub over bookshelves with sub -- that's been my experience. I currently use my M60s without a sub for music, and activate the Hsu STF-2 only for HT.
I know others prefer sub for music -- I am sure it works for them. For me, despite finding a good position, a low xover, and adjusting levels relentlessly, I still spent more time listening to the sub (or wondering if I was listening to it) than relaxing and enjoying the music. And my wife despised the sub in all configurations. As the towers in question become better and more full range than M60s, I can't see changing my mind.
My .02.
