I've got the TOR's on my 05 BA, and they are quite loud (93 dBa I'm told, stockers are abt 82dBa). Short pipe HD is about 110 dBa, I'm told.
The TOR (790 cc) sound is more of a distinctly hollow 'pop-pop' at idle than a deep rumble (HD like), some refer to this as 'english character'. Rev it up a bit, and becomes an aggressive roar. I like it, seems to be getting louder/deeper with the miles. And on decel, sounds great to me. I gather the AI kit gets rid of the popping on decel and pipe blueing (haven't noticed any of that yet). Maybe cuz my pipes are double wall.
If you want the HD rumble kinda sound, I would suggest checking out the other options.

Cheers!


---------- Don 04 BA,TBike pipes,AI,FREAK-150 mains,TBS,42 pilot, 3 turns,\progressive fr and rr shocks, 18T,and lotsa chrome