Trying to decide between a priest or a Mystic. I thought there weren't really going to be that many priests but checking out the forums there seems to be a decent amount compared to Mystics.
This is the "list" that someone put together on the official forums.
Priest Pros
---Burst/AoE Healing.
---Several buffs which last 10 to 25minutes. (both offensive and defensive)
---Absorption Shield (14k damage at 60, resistance to stun/kd while active)
---Ability to kite if needed
---Dodge also slows Movement speed in a small aoe centered on you.
---Dependable self heals
---Easier to heal with.
---Can "cure" knockdowns
---Mass aoe Cure (15 allies in 17m)
---Self rezz restores full hp/mp and stamina (mystic's is 70%hp/mp and 10% stamina)
Priest Cons
---Their sleep is only one target.
---Mp Restoration requires glyphs and devoted charge time
---They don't have any buffs that effect their party's crit rate or crit resist
---Fiery Escape can put you in combat
---Less mobile
Mystic Pros
---Lock-on Heal has a HoT
---Auras (Crit rate Or Run speed) and (Crit Resist Or MP)
---Due to crit rate aura provides greater boost to party dps
---Orbs Can be laid ahead of time, Orbs also act as a "cure over time"
---Better kiter due to DOT being castable on the run
---Teleport skill with a glyph that has a 25% chance to reset the cooldown, KD reactive can also be glyphed to reset teleport. Extremely useful escape.
---Extremely mobile
---Can give their party mana back with orbs, an attack and a passive aura.
---Has a self-resurrect skill that can be cast on party members and glyphed to apply to Self.
---Healing Fairy is very useful. also cures on every heal it casts.
---Can sleep 2 targets
---Has multiple aoe CC skills (stun/fear etc) (all but the stun can be cast on the run)
---Fear completely disables the target in both pvp and pve and is full duration in pvp.
---Ability to lock down bosses with chain CC (once their full arsenal is available)
---Shield can be cast every 25sec (1min 15sec for priests)
Mystic Cons
---Usefulness of Tank/DPS pets are debatable bordering on useless
(tank pet really only useful for soloing BAM's)
---Can't force people to pick up orbs
---Has to depend on Fairy or orbs for self heals
---Orbs, Fairy and Totem do not benefit from weapons heal boost.
---Can only have 1 pet out at a time