Switched to playing Boomkin midway through ToT, and always played/spec'd the standard way as this and ej's forums advised.
Played with the crit build at start of SoO clearing upto Garrosh with it, and although never ranked was close a few times, probably might of ranked if I didn't like DoC so much, but anyways I was messing about on the dummies with my dps and decided out of boredom to try a mastery build, gemmed all yellow sockets 320 mastery and all red Int/Mastery and reforged all crit to Mastery where I could this left me at the 10,289 haste cap, 42% mastery and still with 9k crit.
Tried the dummies again and single target dps was roughly the same if not a little better, so I tried both flex wings and was surprised how high my burst was, my overall dps and also how decent the dps was on trash dotting everything up.
I compared my dps to my previous flex run the day before (when I was crit build and had exactly the same gear) and on every fight it was significantly higher especially on multi add fights like Protectors/Galakras (Protectors I was 25k higher then the previous run) and even single target fights I was 5-10k higher.
Am I being stupid? should I revert back to crit, is anyone else playing with a mastery build?
What mastery lacks mainly is utility. With crit, you gain mobility (which is the big deal) and increase in potential off-heals. Also crit makes your playstyle easier as it speeds up your eclipse cycles and increases the length of your dots.
Sounds like you haven't been using your procs as effectively as you could with crit build. It might explain the difference. The major thing still is the fact that when you need to move out of shit, mastery doesn't help you deal damage while crit does.
Biggest thing as alzu said is movement dps, standstill dps mastery could be slightly better but when you start moving and can't starsurge dps dramatically drops, i've had plenty of times where i've had to move and I can just spam starsurge thus not really dropping any dps.
As others said above me, Mastery lacks that something special. It's a boring dmg increase that offers no mobility, no eclipse cycle benefits like dot extension or procs for faster eclipse switch.
It's also incompatible with FoN which is a major hit to the stat, as well as scaling negatively (not sure if that's the correct term I should use) with DoC.
Overall it's not worth it imo.
The overall effect of trading crit for mastery causes negative scaling with DoC (going from a stat with scaling to a stat that doesn't), but technically DoC is just unaffected by mastery. Proportionately it makes DoC worth less, but the DPS value will be the same.
Anyone thought of doing a Lunar Shower build (I have, never tried or mathed)? T16 2 set, mastery, DoC, and spamming dots in eclipse, using Starsurge procs as they come, hardcasting to the next eclipse? I wonder what the loss would be =P.. Sounds really boring though..
OT: I'd agree that mastery is a boring stat, i'd much rather go crit or haste.
peopl edon't seem to understand that the more crit and/or haste you have the more valuable your base mastery and the amount on your gear becomes because it increases the uptim e of the mastery itself.
Haste reaches a plateau at 10296 so its better to have mastery on the gear than haste at that point, but gemming mastery no. Mastery is only getting better because haste is plateauing off. It's important to understand the relationship between your stat.s
I know that on certain fights my guild prefers to run mastery over crit for the straight damage bonus given during the fight (ex: Galakras) but as most others have plainly put, the "on paper" bonus vs realistic bonus, crit will usually win out in most realistic scenarios.