Parsing the mastery-heavy setup, I show a slight DPS loss (well within the margin of error,) assuming an additional partial Metamorpohsis, with expected scale factors. Again, like my previously mocked posts, the haste threshold is only relevant if you can guarantee an extra Metamorphosis.
I'm going to see if I can improve this sim for you. The stat prioritization looks less then optimal, from the scale factors pictured. Swap haste for crit, drop hit down to ~16.5% and I'm sure you can sim at 34k+.
We also differ on our Bane of Doom.
actions+=/bane_of_doom,if=!ticking&target.time_to_die>=15&miss_react&cooldown.demon_soul.remains>30
actions+=/bane_of_doom,if=target.time_to_die>=15&miss_react&(!ticking|(remains<45&buff.metamorphosis .up))
---------- Post added 2011-09-19 at 09:26 PM ----------
With your BoD change from the default 420-9 I get
Mastery heavy: 34193.6 DPS, which beats the haste heavy setup.
If you want to try to squeak out more BoD damage from the default priority, try:
actions+=/bane_of_doom,if=(!ticking&target.time_to_die>=15&miss_react&cooldown.demon_soul.remains>30 )|(buff.metamorphosis.up&target.time_to_die>=15&miss_react&cooldown.metamorphosis.remains> 177)