Magic looks really powerful, and if it regenerated out of combat, you could start every fight with full mana. I suppose in-combat regeneration would work for prolonging your usefulness, if it was 1 mana/turn and a spell cost like 7 mana, but then people could try and exploit it by running around. Then again, if they want to waste several minutes of their time running in turn-based instead of resting or getting a potion, maybe that's their own business.

Don't talk about 40 mana spells, I'm getting flashbacks to Beyond Divinity.