Haste truely is the better of all combos.... You move through the area devastating much faster, getting rid of those pesky mobs that may put u in a fix. Don't get me wrong, that extra elemental damage is nice, but what for? If u got the right weapons your one shotting everything already anyhow. Haste is truely the superior choice here when it comes to Devastate. Get on some faster speed gear, cast haste, and enjoy. Not to mention if you want to drain some quick life and mana, haste speeds up some of those slower weapons that have more power in em.