I put one in from Best Buy. I got a JVC with detachable face and remote for $200. I don't care about the detachable face and I have no use for a remote when the radio is arms reach away, but I mention them because you get a lot for the money. A good regular CD radio head unit was $125 and up so for the extra $75 I went for the HD never having heard one before.
As far as HD goes, I was skeptical, but even with my old beat up '95 ram's sound system, the HD radio is unbelievable. It is amazing when HD kicks in. when i change a station, it receives like usual. Then if the station is HD, it kicks in about 2 seconds after you are on that station. You will be amazed if you haven't heard it before. And all of the major stations I listen to are HD. If you pick up a major station it's probably HD. I'm about an hour from Pittsburgh PA and all of the big stations I pick up from Pgh are HD. None of the stuff I pick up from the other areas around me are HD.
Oh, and I'd buy one again.
Take care,
Jason