I don't understand what the discussion here is anymore. No it isn't a 50k dps increase, and it is kind of lame when you can't get it in your opener. But you cannot say it barely does anything. ~20% reported uptime on bosses of a 30% haste increase is an average of a 6% flat increase in haste. That is a LOT. That is like getting to wear frost armor and molten armor at the same time. I would say that if you don't notice a difference remember that because it is a crit based spec, you will get varying results wether you have the meta or not. Fire parses do swing pretty vastly one way or another. That being said, after I got my Sinister diamond I noticed my parses swinging upward very noticably.
---------- Post added 2013-05-05 at 09:32 AM ----------
If you are talking reg modes then Jin'Rokh will have higher uptime do to the quickness of the fight and the amount of time that lust is up over the whole fight. Because of the higher percentage of hasted time, the higher chance you have to have the meta procced and the higher % of uptime you have for that specific boss fight.