It depends on which sub your looking at....
I can only express what I have read, thousands of times on the Ultra, but I can also quote my experience with the subs I have and had.
The Ultra has been stated to be excellent for music, because the driver is so accurate, tight and has little if any note overhang... it is also equally as good for HT.
I have had the PB12-Plus in my bedroom, and as it was good with music, it wasn't great for me... more distortion then I cared for but for movies it was spectacular. but it had a touch more note overhang then I wanted to match with my Paradigm Sigs. I sold it for a JL Audio Fathom F112. I love that sub, its superb for music. I couldn't be happier.
I also have Dual PB12- Plus/2's in my Great Room, and I love them for Movies, extremely impactful... they shake the hell out of things like you wouldn't believe. They like the Plus, also are good for music but I like a bit more of a controlled driver. Remember it depends greatly on what kind of music you like, if you like rap and all that bumpin stuff, any SVS sub will handle your needs with no problem, but if you like accurate controlled bass think about steppin up to the big boy... I will be replacing my Plus/2's with a excellent quality DIY sooner or later...