You really wanna go full haste as ele, for reforging haste > mastery > crit (crit is nearly useless as ele). Gems for red sockets 160 int for yellow 80 int 160 haste and blue 80 int 80 pvp power. Haste is just way too good for ele to miss out on. Lowers the global cooldown, speeds up flame shock ticks which equals more instant lava bursts casts. I was on PTR I don't remember 100% my stats but I believe it was 40-43% haste, and 60-61% mastery. Mastery is good as ele, but you gotta think about it, our mastery proc gives us gimped damage 75% of the original spell where as our haste proc (lava surger) gives us a normal lava burst that can still proc mastery. Also haste is very nice for building up fulmination stacks. Especially after some testing on PTR it's pretty obvious that unleashed fury is the dominate spec (I'd say ele blast was equal to it in Grievous gear) but with these high stats the % scaling of unleashed fury seems to scale higher than ele blast damage, meaning crit is useless.
Thank you. I was about to go insane with so many screenshots of stats and none of them close to optimal. And as a few posts above pointed out, 34.99% haste then full mastery will likely be the best possible set up.
Most will say it's best to switch, but I've found using certain glyphs to help with rage and sitting D works better. You can keep higher pressure when being targeted and forced D this way, less threat from being swapped to, and the damage while ignored is still high.