Does spriest get better in DPSing with better gear? I am sitting with 905ish ilvl and I really, really struggle killing Argus normal and other zones WQ npc. With nice amount of haste, will i kill things faster??? When will the gameplay become much more smooth and quick?
If you struggle killing normal enemies, more stats wont help you.
It's a matter of wrong playstyle. My Spriest doesn't have good gear and massdots and kills everything quite fine.
Shadow is quite awkward for that, switching in and out of the mode where you do the most damage. I remember demonology having a similar issue in previous expansions. On my shadow priest alt I've had some success building up insanity off a few mobs, then dotting a load and casting void eruption. The spec feels much nicer in raid content, since you can actually cycle through multiple voidforms before the mob dies.