You clearly know nothing about serious guilds then. A "serious" guild cannot just take another warrior or hunter (both nerfed) for a few reasons, one just being the fact that you need to maximise loot on progression if you stack the most OP classes then some of your warriors won't be getting mythic loot. Another reason is that Spriest are really good for certain fights such as Beastlord Darmac or The Blast Furnace due to MC and lastly, Spriest on a fight like Garosh or Raden were AMAZING because of there burst. Hesp on a previous post explained how good our raid cooldown actually is with the glyph and you can't just bring in Hunters to replace us or else all you get is AotF when VE is raw healing output for the whole raid.
If anyone thinks shadow is weak or just average after the mastery buff they have no clue at all and should honestly go play a simple game like League of Legends.
Separate to all the shenanigans, the buff to mastery and its effect on talents basically means Insanity is going to become stronger now, compared to FDCL or MB. Is it safe to say Mind Flay Insanity has a double dip effect from the buff? I just don't want to spout random stuff without it being true so I'd like to know what everyone else thinks