Well when I download it from any of several windows computers it is always a .ZIP
BUT when I type the URL into my phone's browser the .APK downloads and installs "as advertised".
It's not just a simple matter of file extension naming either because I changed the file extension of the .ZIP in Window to .APK and it did not work.
The files contained in the .ZIP are exactly what gets installed into /system when I run the .APK
...interesting. I would like to learn more about what's up with all this but for now the important thing is that (with your help) I got the app installed and working on my DX (for free) and am ready for fun with custom ROMs.