Most times it feels like this: WHM gets nothing (because a lot of people play it so it must be perfectly fine). SCH gets a dps potency increase. AST will get a DPS and healing potency increase, plus at least one spell will be a few MP cheaper.

Faerie bugs stay as they aren't able to fix them before the next expansion, cards stay like they are OR Sleeve Draw gets a CD reduction so that you will have to switch between targets even more often.