well here's my 2 cents. I have the HT speakers and amp setup, used the rear speaker wire for my lower fairing 2ohm HT speakers. at 80mph it sounds awesome. here's what I did to help, the back of my lowerpods i lined with DynaMatt to stop and resonance, and added some stips of it in my upper fairing near the speakers, (this should be done no matter what system you use). also have the Clearview GT stock windshield which helps the sound.
all HK stereo's will distort over 3/4 volume, thats including auto vol control. I set my ipod at full blast, adjust the stereo at 1/2 tops, maybe a little lower. It's loud.
My buddy has the HW system, it's loud too but not near as much bass as I have. and near 500 $ more for his.
I'm happy with HT