Breakdown of the classes, and how they play, based on current meta/popular PvE Spec.  (Feb 1, 2017)

>Blade Master - Fire
Tank/Defensive Buffs. Focuses on keeping up Draw Stance and Conflagration buffs to gain access to high damage RMB spam.
Defensive party utility with HM Block party Iframe.
Considered good currently, though their outlook going forward is a little downward sloped.

>Kung Fu Master - Fire Hybrid
Tank/Offensive Buffs.  Focuses on stacking and resetting Searing Palm using mutilple skills to do so.
Offensive utilty with Blue Buff, Tremor, and Searing Palm buffs.
Considered good currently, and expected to remain good going forward.

>Assassin - Lightning
DPS/Offensive Buff.  Focuses on keeping Stealth up and Poison stacking while using RMB/F animation cancel.
Offensive utilty with Blue Buff.
Considered good currently, and expected to remain good going forward.

>Soul Fighter - Frost
DPS/Heal.  Focuses on stacking Chi with RMB/F to gain access to V skill for burst damage.
Healing utility with Chi Burst and party Revive.
Considered ok currently, expected to become good going forward.

>Blade Dancer - Lightning
DPS/Grab.  Focuses on maintaining Draw Stance and Lightning Surge buffs to gain access to LMB/F animation cancel for damage.
Multiple utility with Grab and Maelstrom Party Iframe
Considered ok currently, expected to remain ok or slightly above that.

>Destroyer - Earth
DPS/Grab.  Focuses on LMB/RMB animation cancel with Fury and other smaller skills for burst damage.
Grab for utilty.
Considered bad currently, expected to move to ok or slightly above that.

>Warlock - Shadow
DPS/Offensive Buff.  Focuses on skill resets to consistently gain access to 4 for damage mixed with RMB/F.
Offensive utilty with Soulburn.
Considered to be good currently, expected to remain good going forward, though slightly below current.

>Force Master - Fire
DPS/Defensive Buff.  Focuses on maintaining Burn debuff while cycling LMB/RMB/2 and a few burst damage skills.
Defensive utility with Frost Sheath.
Considered to be good currently, expected to remain good going forward, though slightly below current.

>Summoner - Earth
DPS/Heal.  Focuses on Maintaining Ivy Poison for bonus damage and additional skill cycling to gain access to Super Sunflower, while using LMB/RMB for primary damage.
Mutliple utilty with Heals, all 3 types of double CCs, and Cat taunt/pin.
Considered to be ok currently, and expected to remain ok going forward, though slightly below current.