The AM14A was a Two Way device. It could be polled for its state.
The AM466 is just a receiver. In that case it could make a difference to which was picked.
Some just look like what Icon represents the device on AHP
Now the new Soft Start modules act more like the two way modules and maybe why X10 said call them that way.
I even looked in the Security Tab in AHP as X10 lists the Powerflash as a Security Module.
I was trying to think of what maybe a close choice for a PowerFlash in AHP; but so far no ideas.