Sir Osis missed one other feature of going to 120.
If you are going to do BODs, you'll want 120 skill, and not just for filling exceptional plate BODs.
Under 110 skill, BODs break down as follows:
50% Weapon BODs
25% Iron Armor BODs
25% Colored Armor BODs
At 110.0 to 119.9 Skill, BODs break down as follows:
50% Weapon BODs
15% Iron Armor BODs
35% Colored Armor BODs
At 120 skill, BODs break down as follows:
50% Weapon BODs
5% Iron Armor BODs
45% Colored Armor BODs