Compression molded is a clay chip in a compression mold.
Composition is made by injection molding and is a plastic and clay composition.
Yes you can tell a difference. Lay an arodie next to a chipco unicorn and you will see the difference.

In Nevada all chips are supposed to be the same weight and 39MM. I do not have the gram weight in front of me, but will post it later.

Atlantic Standards new chips are less than 39MM ( such as the A Crest mold)

Paulson is the only Co that has clay molds with enough capacity to produce clay chips at a reasonable cost. I have forgot the count but say, AS or TR King can run 16 chips at a time, Paulson can do 50. ( meant as an example only)

When Paulson changes to injection molds, there will be no more clay chips. I have no knowledge that they are even thinking about this at this time. I believe it will come in order for them to compete. They are doing it now because they produce chips in Mexico.