NHT Sub TWO I??? Any comments?

Was wondering if this is a good quality "music only"
sub or more for HT?

Any preference over the 10" or 12" models?

Any comments & thoughts appreciated. (other subs???)

System:

Creek 5350 SE Integrated (85 W/PC)
Montana SP II MK II speakers
Music Hall MMF 25 cd player

System as is sounds fantastic and I do not want to
muddy it up with flabby...boomy bass.

Thanks,
Bob