Thought the only difference between "standard" and "classic" was what processor they run on. I.e., Classic/68K/PowerUp hardware, or newer (Sam, X1000, X5000, etc.). Isn't there actually like six different versions?
There's seven different version available, Classic, AmigaOne, Sam440, Sam460, Pegasos2, X1000 and X5000. Then there's the A1222 version that's currently in alpha/beta. There are also the unreleased versions for the IBM Elap PDA, the LimePC netbook and the Mac Mini G4. That's eleven in all but I seem to recall that years ago Bill Buck claimed that it ran on Efika so if confirmed it would bump the known number up to 12.