Usually i wont use heal if my enemy just mobs, but boss? Sure im heal sometimes if my teammates dying alots of times, but i hate when someone say MANA!! to a mage, when a mage not using heal thats mean the mage should use potion for mana too, not only the one who shout at mage, i myself usually use alot of mana pot in elites and sometimes during fast run in normal, if in arena? Well look at the boss first. I think its about how you matching yourself with your teammates conditions depends on thier skill play.