I don't want to be too much the curmudgeon here, but it never bothered me before. So here goes.
This is an absolutely useless, dead technology. It was dead out of the gate. You can't tell me that it means anything to "the listener" who doesn't understand, or more importantly finds no "whoopee" factor about this, and isn't about to spend whatever to get it in their car or home. I applaud Bill for getting it done under pressure, as he was assigned to do, but in the beginning, middle and end, it's a useless technology and a massive waste of money.
Chris, I appreciate your enthusiasm for all things radio, but this is junk science. There was no problem to solve here that this remotely addresses. IT IS A WASTE OF TIME AND MONEY.
As to your consideration of HD additional channels, just remember the more you add to this bloated nonsense, the more is actually taken away. The main channel at its best, is less than you can get from the least iPod. Take from the main to add 2's and 3's and you have a real audio mess in your headphones. As if anyone was left that gives a $hit about audio quality.
I was against this from the outset. The problem with radio is not analog, and the solution is not digital garbage.