This is going to be a long list so I’ll edit this one…
Wpvp;
Healing: Believe it or not, you actually can destroy people 1v1 in world pvp as a healer. The name of your game is to cast SWP, let them dwindle down, and win through your massive mana pool. The only issue you really have is against hunters which can mana drain you and there is really nothing you can do. Your only hope is to go all out on them.
But, you actually destroy mages. Ice barrier? Dispell. Mana shield? Dispell. He roots you? Dispell. Cast SWP and mana drain, if he counters it then just cast a healing spell on you. If you play it correctly or your not grossly undergeared you will win 100% of the time.
Not to mention fighting against other healers in smallish fights I believe you have the advantage as long as you have a team that can peel for you. Offensive dispells and mana burns and crazy good. Especially if you’re horde because you won’t have to deal with shamans and Paladins are basically sitting heal turrets that are asking to be burned.
I won’t lie, if you have a team who can’t peel or you’re undergeared melee will run through you. Which is why I personally went dwarf for that extra little defense.
Shadow: Oh buddy you’re in for a treat. Besides SL locks which can be pretty annoying, you’re destroying everyone and everything if you have full mana. Melee have a tough time doing any damage at all to you because of IF and shadowform. Casters you eat alive with offensive dispells and your mindblast crits on top of your blackout procs.
Just be prepared to go oom a lot and drink as much as possible out in the world as starting a fight when you’re almost oom means you’re dead.
Bgs;
Healing: I believe you’re the single best healer for bgs. Yes, Paladins are the defensive utility kings, but a priest will turn the fight in an instant if you play it correctly. Offensively dispelling important targets, mana burning if you’re being ignored, instant heals of every flavor, and even doing cheeky stuff like MCing other healers off of LM or BS will win you fights.
Shadow: this is more of a… pug spec where you’ll shine. You can sit on flags and defend them decently, you can really mess up mages 1v1 or others… but you do oom quickly which sucks unless you’re just absolutely destroying them
Pve;
Healing: once again, I think you’re simply the best. Everyone wants a priest. You got a Rez, amazing buff, raid heals AND main tank heals, you have utility for the undead 5 mans so you can cc, you will have NO issues finding any groups whatsoever. Just for the love of god, don’t PW:S the warrior tank unless he is about to die
Shadow: this is sort of controversial… but in my opinion, if you have a dedicated guild and don’t really pug a lot shadow is just fine. No, you do not need top min/max dps to clear raids. No, you will not wipe your raids because they brought an spriest. No, spriest are not useless. Shadow priest is just fine in raids, they provide another rezer in case of wipes to speed things up, they also give your warlocks a %15 damage increase which is amazing especially in later raids. And they can off heal if too many healers die in a fight with little to no issues. On top of this you can 100% heal 5 mans as shadow. Yeah if your group makes bad decisions then you might wipe because of your spec. But if they play safely it’s 100% doable.
All in all priests are awesome for whatever you’re looking for at end game.