Skaros said:
Now someone just explain to me how I'm wrong and there are enough benefits to justify it from the cost-benefits point of view.
Well, okay, so you give up three caster levels in your primary spellcasting class, but in return you get Spell Versatility and the Drifts.
Think of a Cleric3/Wizard3/Geomancer10. He put all of his +1 caster levels into Wizard, so he's a 13th level arcane caster instead of a 16th level arcane caster. But he has ten drifts to help him out that probably offset that. Even if you go with a set of ten drifts with the idea that you want to avoid obvious physical effects he can gain:
Drift 1: Hair a tangle of short vines.
Drift 1: Touch causes flowers to wilt.
Drift 2: Swift as an elk, +5 movement.
Drift 2: Comely as a dryad, +4 to Diplomacy checks.
Drift 3: Eyes sharp as an eagle, +5 daylight Spot checks.
Drift 3: Eyes sharp as an owl, +5 dusk/darkness Spot checks.
Drift 4: Nose sensitive as a hound, gain Scent.
Drift 4: Boar's ferocity, continue to act without penalty when disabled or dying.
Drift 5: Tremorsense of an earthworm, 30 foot range.
Drift 5: Senses of a bat, gain Blindsight feat.
So, for three caster levels you gain +5 to movement, +4 to Diplomacy checks, +5 to Spot checks, Scent, Ferocity, Tremorsense and Blindsight. And armored casting. That seems like a decent tradeoff.