...you always need haste. haste makes your dots tick faster. and is more of a dps boost than crit, always. the only time haste stops being a big boost, is when you hit 1 sec gcd, and even after that haste is still a dps boost, just not as much of one. in fact, if you can get to the next tick for immolate, haste is more important than hit due to conflag.