I tried 50 mana for max aoe dmg, witch can be fun to play, but not reliable.
In 8v8 mana/light is perfect: your job is mostly to spread NS (coordinate with your bard to rupt demezzers/ns cleaners, cuz it is useless to mezz or NS if the enemy insta clean it, even if sometimes it buys you couple of seconds to instakill a targhet), spread desease and debuff MA witch than you gotta nuke with base DD (enchanter will debuff for it and menta will stun it).
So: spam NS and when is called switch to MA, desease it and debuff than nuke.
It depends on how you plan to play. If at lower RR, you plan to stick with Pilz and run in the BG, I would seriously consider Void. You'd be able to leech RPs with the gtaoe, and bolts are still useful at keeps.