Beyond the differences in blade finish (CG/Urban - coated, LE - Satin, DC - double cut/bead blasted) the original CGDM used the Busse basic handle, most of the later DMs (except the DMLE) used the tiny bit longer small Res-C handle.
In addition, the original DM is saber ground with a blade thickness of approximately .285 while the other DMs were flat ground with a blade thickness of approximately .250.
I've ignored some of the limited special releases but hopefully I got most of it right.