I have a warlock who is also an alchemist. He has his alchemists enhancement flask which gives him 320 intellect. He also makes Elixir of the Monk which with his alchemists mixology gives him around 990 mastery. He's affliction for heroics and raids. For raids its Flask of the Warm Sun hands down. BUT... For five man heroics between the 320 intellect flask and the 990 mastery flask, which would do him greater good given he's around 471 overall item level and sports over 21K spellpower unbuffed.