Oh yeah I totally forgot about the slight difference with model A. don't they also have a slightly different color scheme or is that only with the model "a" the 8-bit version.
Also Model X, and Z are slightly different mainly with the closed vest and shoulder armor. The others have that open vest design like ZX nad they have no shoulder armor.
The other four have a uniform design but they still look sinister, but then again it just might be the sinister nature of their chosen ones. I though i read somewhere that the four chosen ones for models H,L,P, and F may have been brainwashed by either Albert or Model W and that the four biometals are working against their will (they would never help model W, they would rather destroy it). As far as the four chosen ones being brainwashed im not exactly sure.