Nice review. I concur, yet am only running one unit using First Horn's--high efficiency.
I found the same results with speaker cables. Started with zipcord and it was thin. Moved to Audioquest (red one's) and it didn't improve much. Then went to the Anti-Cables and it turned the corner.
I can't wait to try it with a tube preamp whenever the tech gets around to finishing it, I would guess it will do wonders to improve even further.
I found the Trend to be a much better product than the newer Sonic Impact unit, which was sold almost immediately upon finishing break-in. L'wood