I've been informed about the set bonus for the Spellcaster jewelry set, and apparently you are given +25 Vitality and +25 Energy. The vitality doesn't make sense since mage-based classes are glassy enough and don't need vitality. Wouldn't it make more sense to have +25 Sorcery and +25 Energy instead?
I don't know what the set bonuses are for the Melee and Ranged sets but it makes more sense to have these bonuses:
Spellcaster Set: +25 Sorcery and +25 Energy
Brawler's Set: +25 Vitality and +25 Melee
Greenwood Set: +25 Focus and +25 Ranged
Maybe each set could also give +10 Vitality as a third bonus.