I've said this on another board, and I'll say it again here. I'd be a true believer in HD Radio, but the hardware is just too awful.
A couple months ago, I found a special on the Gigaware HD Radio add on for the iPhone. I was able to get it for $17 at Radio Shack, and the app is free. I figured it was worth a try at that price. So, I went to Rat Shack and picked one up. The staff there didn't really know about HD Radio, and it took about 20 minutes of both of us scouring the store to find one of the two units they had left in stock. I'll cut them some slack about brand awareness. After all, there are only two stations where I live that broadcast in HD, and the online campaign is pretty anemic.
So, I tried it out and found some good, some bad, and a whole lot of ugly.
The good: The radio tuner is easily the best one in my house. Yes, really. I have no trouble picking up a station 64 miles away, and the only antenna it uses is my headphones. I can also plug some computer speakers into my HD Radio adapter, and I get the same results. The HD component of it works reasonably well, too. For the most part, the actual tuning capability they promised on the unit works as advertised.
The bad: The HD component can't decode one of the two local stations that broadcasts in HD. I'll cut them some slack on that since I live just outside (1-2 miles) of its city grade signal contour. HD Radio isn't something you're supposed to expect to get outside of city grade. Besides, it's a True Oldies affiliate and has no HD-2 stream. Some loss! I also took it to Kansas City about a month ago and found it did an admirable job with most of the local stations. It was, however, able to find an HD stream for KCUR 89.3 but never could decode it despite being just a few miles away from the transmitter. The Gigaware HD tuner also doesn't offer AM, though I'm not sure that's a very big loss.
The ugly: Beyond the tuning ability of the radio, it's absolute junk. Tagging a song crashes the app more often than not. I hope you don't plan on listening to a single station for very long. Listening for more than a few minutes will freeze the in-app tuner. The kicker, however, is that the app will disconnect from the unit every 10 minutes like clockwork. You can get around it by not letting your iPhone sleep and not locking it, but that depletes your battery faster, and you can pretty well forget putting it in your pocket and using it as your radio when going for a walk or hitting the exercise equipment at the gym.
HD Radio had some potential. It might be something that could make a comeback, but Ibiquity is going to have to invest something in its product. Simply put, people aren't going to shell out money for something that doesn't work, and you can't blame most car manufacturers and other EOM device manufacturers for not wanting to invest in crap. I don't blame them for not putting HD Radios in their cars when, if they work like my Gigaware tuner, they'll break before the end of the warranty, which means the manufacturers will be on the hook to fix them.