I have an ilvl of 375, but I'm at 16.89% hit, 2610 (20.38% no DI or 5%spell haste) haste, 1104 (15.78%) crit, and 520 mastery.
So it is very doable
Don't know how credible it is, but my simcraft says at my haste level, crit is now better than haste point for pointhaste is our best stat, even after reaching the plateau.
the only point where crit can become better as haste is after reaching the hast softcap where you get 1 second shadowbolts.
as far as i know, we cannot reach that softcap yet so keep reforging to haste like a madman ( assuming you are hitcapped)