Before we begin, credits to raxeus for lending me his MG00R for this short review.

THEY USE DIFFERENT MOULD.

Judging on that one image I uploaded you probably won't notice the length of the Raiser binders are actually different in length. The binder on MG00R is about 7-8mm shorter than that of MB00R.

The clear 'green' plastic of both 00R are of different colour tones.

MG00R has shoulder heavy issue as the binders cannot be raised as high as that of MB00R's.

MG00R has LED illuminated head, GN drives and binders; MB00R has no LED illuminated parts.

MG00R has problem with Action Base, spender keeps dropping.

The Raiser itself is very different on both mechs, more poseability with the MB00R.

Shape of arm of both mechs is different:

GN Shields of MG00R has very loose joints, they drop every now and then when I try to pose it.

Parts that I found which are of different proportions/designs/joints:
Shoulders *MG00R has rounder/fatter shoulders*
GN Drives *MG00R has rounder/fatter GN Drives*
Spender *they wear different size*
Pelvis *better posing with the MB00R*
Side skirts *different joints to hold the swords, have to swap parts on the MG00R to hold the swords; less tight connection on the MB00R*
Thigh *different design, see photo*
Forearm *fatter and shorter on the MG00R*
Biceps *shorter on the MG00R*
Binders *shorter on the MG00R*
Circular green clear parts *smaller on the MG00R*
Waist *more joints on the MG00R but may cause back heavy issues*
GN Sword III *slight difference on design*