What race for shadow priest I should choose and why?
The best shadow priest for the horde and for the alliance..
Well for Horde troll is the best with their Berserking and after Trolls is Goblin it's only a minor difference so if you really want Goblin it's also almost as good the haste value between goblin and trolls racial is not big at all, for alliance Worgen is by far the best and after them id say would be draenei bcus of the hit but then i think that the racial of draenei is shared to everyone in the raid grp so if you have a draenei in raid you can go human because it has got like some extra hit aswell but not quite sure on that.
I went through this in my guide at one point or another. For horde yes - troll then goblin.
For alliance - Worgen (1% crit), Dranei (1% hit), Human (.5% hit via Human Spirit), Gnome (5% mana pool)
The reason why worgen wins out is that 1% of crit is about 180 points of stats, while 1% hit is only about 100 points of stats. Every class is going to be hit capped whether the cap is 17% or 16%, so the value of hit becomes near the value of crit. So in the end getting 180 stat points is better than 100 stat points, regardless of what type. There was a point early in the expac (in tier 11), where excess hit converted to haste. This was the only situation this expansion where it might've been "equal" to be a dranei over a worgen. Even then, the moment was short-lived.
and the worgen sprint comes in pretty handy on alot of fights (okay not so many in dragon soul but in general its a live saver or nice dps increase especially because priests dont really have anything to move faster [inner will is only 6% faster than moving with the boot enchant-> not really worth switching])
If you want the best racials then pick the what people have already suggested but if you just want to be a bad ass then id choose Undead for Horde and Dwarf for Alliance!
for casters who gain back %'s of mana i always choose gnome. 5% sure does add up in the end.
is´t really close what troll lets get a bit ahead is that you can time it together with trinkets burstphases etc
yes basically what Ravyna said. Also you have the fact that fights never end on a perfect multiple of the cooldown of an ability. So in actuality all "on use" items are typically a tad better than their average.
For the troll CD, we say 10/(3*60) = 5.56% uptime. However, unless the fight ends EXACTLY at 3 mins, 6 mins, or 9 mins, the uptime is actually a bit better than 5.56%. You still want to compare it to the alternative - if 1% haste was significantly better (on paper) than berserking, then it would still be better. But in general if you have two abilities - a static and an on-use that are about equal - the on-use will be a smidgen better.
(As an aside, this is typically why on-use trinkets always appear to be under-budgeted compared to static trinkets.)
Goblin is better. Dps difference is irrevelant small but goblin rocket jump wins. I have no idea how well simcraft uses troll racial, but doubt it makes any big enough difference. Its possible troll racial is helpfull in burst phases (though long cd limits it), but just same goblin can reforge for more mastery than troll and get more burst every mind spike phase reliably.
T13HC, all buffs, fight lenght 450sec+-20%:
Troll: : 49868 dps
Goblin: 49885 dps
Does it really matter what class is "best", I would go for aesthetics over a 20 DPS difference.
Disregard all that math and go for what you LIKE how it looks. 20 dps wont make a difference. All racials are below RNG.
For alliance worgen for sure, horde is troll or goblin depends if you like 1% haste or 20% on 3 min CD
As others have already stated, if you're min/maxing, then Worgen, Draenei, and Human in that order; Troll or Goblin on the Horde, but it is pretty much a wash.
I like to be Human since Every Man for Himself is pretty amazing at times and gets you out of sticky situations, such as the Warlord fight in DS; it's saved me a few times on that fight alone. (Hey, I'm only human, literally!) Also, I like to PVP on the side and the human racial saves me a trinket slot.