Hopefully it is upgrade like this:

Duelist's Chapeau +2

Def: 30 HP+30 MP+30 MND+10 Enfeebling skill +20 Enfeebling magic potency +10% Adds "Refresh II" effect Lv.95 RDM

And not upgrades like this:

Def:27 HP+20 MP+20 MND+5 Enfeebling skill +15 Adds "Refresh" effect Lv. 95 RDM

Another example:

Warrior's Mask +2

Def: 38 STR+10 DEX+10 Attack+15 Double Attack+5% Haste+7% Enhances "Warcry II" effect Lv.95 WAR

Not:

Def: 34 DEX+8 Parrying Skill +10 Enmity+3 Enhances "Warcry" effect Lv.95 WAR

Some kind of example would be nice.