I have had my HT3's I think since April '06. I was a little dissapointed when I first got them because for me, they were a little thin and bright. After I replaced my Odyssey Tempest pre with a Modwright SWL SE, things got much better. Good recording sounded great, but not so good recordings and hard music sounded on the bad side. Overall, the HT3's were still on the thin side, lacking heft. Hard rock and other noisy type music still did not sound very good.
Just last week, I bought a modified Ack! V 1.0 to go with my SB3, and wow, things got much much better. Absolutely no more fatigue, it sounded like vinyl, bad recording sounded good again, and I could blast Tool louder than I wanted with no harshness whatsoever.
A couple of days ago, I started experimenting with a Behringer DEQ2496, and things are very promising. I finally have a hefty, yet crisp and detailed sound. Now I know why people have been so excited about these speakers.
There were two factors that caused the lackluster sound of the HT3's: The Odyssey Tempest, and the DAC and analog output of my SB3 (with full Vinnie mods).