I'm having some conflicting data between Shadowcraft, Ask Mr Robot, and my personal experience with the spec.
Generally (in the past), Haste has been a stronger stat for Mut, as it gives us more Envenom uptime and makes it easier to fit more spells into an Envenom's duration.
Now, I'm seeing Crit edge out Haste as I get into higher ilvls.
I know Crit will proc Seal Fate and make Dispatch hit harder (RNG RNG RNG), but does it do anything else?
As an example, Shadowcraft wants me to reforge Haste->Mastery rather than Crit->Mastery on my 496 Shadow Heart Spaulders because it is valuing Crit a few decimal points higher than Haste.
Another question: Since the stat values are SO close, is it wiser to keep the Haste in order to make using Combat w/ Mut reforging a little smoother/easier?