HD radio sounds much worse than internet stations at 128.
Most of it available here at least is not that great, you can clearly hear the artifacts. Any decent analog tuner sounds much better to me.
HD does not stand for high definition, leave it to the marketing people.
From the crutchfield site first thing that popped up in google:
"Originally, the initials stood for "hybrid-digital," because the digital signals were carried with the analog wave.
According to iBiquity Digital Corporation, that's been changed, and the letters "HD" now don't stand for anything.
Some articles and news stories have erroneously assumed that "HD" stands for "high definition," which has contributed to the confusion between HD Radio technology and high-definition TV."