• HD Radio
  • There are very few radios that support this. Why?
  • I have HD-Radio channels available locally. In particular, WBEZ broadcasts it:
    91.5 HD1 WBEZ Chicago Public Radio, News/Talk
    91.5 HD2 WBEZ Vocalo, News/Talk
    89.5 HD1 WBEW Vocalo, News/Talk
    89.5 HD2 WBEW Radio Arte, Spanish
• apt-x, a Bluetooth codec
• for Android phones, the key thing for support is the AOA protocol. AOA 2.0 is the latest
• Android Auto — allows you to use the car radio's touchscreen, as a proxy for the phone's touchscreen (pricey!!)

Ultimately I chose among these three:

HD-Radio:
    Clarion CZ505               -- It had very few reviews, so there may be problems that weren't uncovered.  But I went ahead with this one.
    Sony MEX-N6000BH            -- It can't pause Bluetooth when you step away?  WTF?
    Pioneer DEH-X8700BH         -- It has a very novel interface, which some folks love, other folks dislike.

non-HD-Radio:
    Pioneer DEH-X6700BS         -- Uniformly good reviews.