HD car radios, worth getting?

[Rocket Power]

I have been hearing a bunch of commercials for HD radio. What's the deal with it? Does it sound better, just more stations of the same old crap? Is it worth buying a new car stereo or is satellite still better?
In the words of the bad guy in the beginning of Dirty Harry, "I gots to know":goof

[Windsors 03 Cobra]

If you are a radio person there are quite a few side stations that play "just music".
I would like one but I have enough radios and they all work. Its better than AM STEREO :D

[Karps TA]

AM Stereo is what comes to mind when I hear HD Radio.

Personally ever since I got Sirius 3 years ago, I can't imagine life without it.