In my adventures of Shadow I have found that 20-24% static Haste is a must. Too many people try to balance Haste and Crit, but really, Haste is the runaway stat. Second, the further into Heroic BoD and more importantly, the 3 Azurite pieces from BoD will dramatically change your shadow priest. I can now have up over 76% haste with gear procs, doubling my SIM dps (and keeping me in the top 3 of raid DPS).
Before H/BoD I was at 380 ilvl and 16% Haste and 19% Crit. Now I’m at 388 ilvl and without buffs, 19% Haste and 16% crit and I feel WAY more fluid.
Unhuman, Skywall, Horde