Energy advantages over mana AFAIK, the only benefit of energy is in attaining maximum mana - it helps in nothing else, unlike Diablo. I've reviewed the maximum mana formula and here's my immediate conclusion. Assuming a Barb reached CLvl99 with no added energy, there'd be an obvious benefit of %mana if it existed, since it's multiplied against a sum which includes item mana, while item energy simply gets added to the end. So item mana, point for point, will be the same or better than item energy, but item energy would only be the same as item mana if no added energy or %mana exists. Can the same be said for all other classes? The maximum energy from items appears to be: 340 for a Barb, 330 for a Sorc, 325 for everyone else. I suppose there must be an easier way to figure out the ideal amount of item energy versus other mods to attain a healthy maximum other than casting until everything is dead or you run out of mana, with the latter meaning add more. I started by deciding end gear item energy summed with added energy to reach potion critical of 200. Is that a good place to start?