The primary difference is that the core is inverted (opposite).  The Supreme Justice has the Justice core, but inverted, or upside down.

The original Justice's shell is One-7, and the Supreme Justice (solid) is One-7 Plus.  The Justice Pearl's shell is SuperFlex reactive, and teh Supreme Justice Pearl is Mach-I Reactive Pearl.

SJ - rg=2.53, Diff=0.051
SJP - rg=2.51, diff=0.054
J - rg=2.56, diff=0.045
JP - rg=2.52, diff=0.050
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Semper Fi! AMForce Rocks!