So I've read all the threads in the destro how-to thread...several times in fact and reforged a gazillion times with various haste, crit and mastery. I did pretty well dps wise but then today I looked at my character on Battle.net and read this bit...you know the bit...
Mastery: Emberstorm 'Increases the damage of Immolate, Incinerate, Fel Flame and Conflagrate by 9%. Increases the effectiveness of Burning Ember consuming spells by 24%.
I really started thinking about that. By going Mastery > Haste and Crit we improve our damage for our 'regular' spells and also our Chaos Bolt, do we not? If memory serves, crit increases Chaos Bolt damage by 30% but with enough mastery, won't you also reach that 30% damage AS WELL AS increasing the damage from your other spells? I simmed myself last week with every possible permutation of mastery, crit, and haste (only 9 variations) and the DPS increase/decrease was piddly...seriously...piddly...we're talking on the order of a 100dps or so which, in a raid environment, is nothing.
The destro guide says stack mastery for cleaving but that's not the way to go for single target. I'm at work so can't run a few LFRs to test and see but from just reading the above about Mastery, seems to me that going all mastery would increase your damage across the board for all spells.
I know I'm missing something. Again, I'm at work so can't test this myself....what am I missing!!